Bisimide compounds, polyimide resin composition prepared therefrom, and carbon fiber-reinforced polyimide resin composition

ABSTRACT

A moldable polyimide resin composition which has melt-flowability and excellent processability in addition to essential heat-resistant of polyimide and comprises an aromatic bisimide compound and polyimide resin. A further aspect relates to a carbon fiber reinforced polyimide resin composition which has excellent mechanical strengths and comprises a carbon fiber coated with aromatic bisimide compound on the surface and the polyimide resin. A still further aspect relates to a novel bisimide compound which is very useful as the aromatic bisimide compound in the composition.

This application is a divisional of application Ser. No. 07/934,681,filed Nov. 9, 1992, now U.S. Pat. No. 5,457,154.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a bisimide compound, a polyimide resincomposition comprising the bisimide compound, and a carbon fiberreinforced polyimide composition comprising a carbon fiber coated on thesurface with the bisimide compound.

2. Description of the Related Art

Materials having more excellent high-temperature characteristics haverecently been required in order to enhance performance and reduce weighton various industrial materials in the fields of electric and electronicdevices, space and aeronautical equipment and transport machinery. Inthese materials, polyimide has mechanical strength, dimensionalstability, flame retardance and electrical insulation properties inaddition to its excellent high-temperature resistance, and has hencebeen widely used in the above industrial fields. Polyimide of highmolecular weight, however, generally has a high softening point and isinsoluble in almost organic solvents. As a result, many difficultieshave been encountered for the use of polyimide.

ULTEM(Trade mark of General Electric Co.), a representativethermoplastic polyimide resin, has superior heat resistance andmechanical strength compared to general purpose engineering plastics.Consequently, it is called a super engineering plastic and widelyinvestigated for use in electric and electronic devices, machines andautomobiles.

Accompanied with the recent progress of technology, it has been demandedto develop a novel thermoplastic polyimide resin having heat-resistanceand mechanical characteristics which are superior to ULTEM.

For example, U.S. Pat. No. 4,847,349 discloses a process for preparingpolyimide resin by reacting etherdiamine with tetracarboxylic aciddianhydride. Japanese Laid-Open Patent Hei 2-018419 proposes a processfor preparing polyimide resin by reacting 3,3'-diaminobenzophenone andtetracarboxylic acid dianhydride. Both patents have provided novelpolyimides having heat resistance and mechanical characteristics whichare superior to conventional polyimide.

The above polyimides are much superior in heat resistance and othercharacteristics to common engineering plastics represented bypolyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polysulfone and polyphenylene sulfide. However, increasedmolecular weight lowers melt flowability and melt processability of thepolyimide is still inferior to these engineering plastics.

In order to enhance the characteristics of polyimide resin, mechanicalstrength in particular, fibrous reinforcement, particularly carbonfiber, is generally incorporated.

Carbon fiber is frequently used for carbon fiber reinforced plasticswhich use epoxy resin as a matrix and hence epoxy resin is commonly usedfor the collecting agent of carbon fiber. As a result, the epoxy resincollecting agent is effective when thermosetting resin such as epoxyresin is used for the matrix. However, epoxy a resin has poor adhesionto polyimide resin and resin composition having good mechanical strengthcannot be obtained.

A process of using polyimide resin for the collecting agent of carbonfiber has been disclosed, for example, in Japanese Laid-Open Patent Sho53-106752. However, polyimide resin must be generally processed attemperatures higher than 300° C. and the collecting agent decomposes byheat in the processing step to cause problems such as formation of voidsand reduction of weld strength. Further, Japanese Laid-Open Patent Sho56-120730 describes a process for using a carbon fiber collected witharomatic polysulfone resin. However, the process leads to merely a smallincrease in mechanical strengths and has not yet fully satisfied desiredcharacteristics.

An object of the invention is to provide a compound having outstandingprocessability in addition to excellent heat resistance.

Another object of the invention is to provide a processablepolyimide-based resin composition having very excellent melt flowabilitywithout impairing the essential characteristics of polyimide.

A further object of the present invention is to provide apolyimide-based resin composition having excellent mechanical strengths.

SUMMARY OF THE INVENTION

As a result of an intensive investigation in order to accomplish theabove objects, the present inventors have found that a polyimide resincomposition comprising an aromatic bisimide compound is excellent inmelt flowability and processability and that a polyimide resincomposition comprising a carbon fiber coated with the aromatic bisimidecompound on the surface has excellent mechanical strength, and furtherhave found a novel bisimide compound which is very useful for thecomposition. Thus, the present invention has been completed.

That is, one aspect of the invention is a bisimide compound representedby the formula(1): ##STR1## wherein A is a divalent radical selectedfrom the group consisting of radicals having the formulas: ##STR2##wherein X is a direct bond, a divalent hydrocarbon radical having from 1to 10 carbon atoms, hexafluorinated isopropylidene, carbonyl, thio orsulfonyl, and Y₁ ˜Y₄ are individually hydrogen atom, lower alkylradical, lower alkoxy radical, chlorine or bromine atom, ##STR3## and Ris a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember.

Practical compounds are a bisimide compound represented by theformula(2): ##STR4## wherein X is a direct bond, a divalent hydrocarbonradical having from 1 to 10 carbon atoms, hexafluorinatedisopropylidene, carbonyl, thio or sulfonyl, Y₁ ˜Y₄ are individuallyhydrogen, lower alkyl radical, lower alkoxy radical, chlorine or bromineatom, and R is a divalent radical selected from the group consisting ofa monoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember; a bisimide compound represented by the formula(3): ##STR5##wherein R is a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected each other with a direct bond or a bridgemember; a bisimide compound represented by the formula(4): ##STR6##wherein R is a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember; a bisimide compound represented by the formula(5): ##STR7##wherein R is a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember; a bisimide compound represented by the formula(6): ##STR8##wherein R is a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember; and a bisimide compound represented by the formula(7): ##STR9##wherein X is a direct bond, a divalent hydrocarbon radical having from 1to 10 carbon atoms, hexafluorinated isopropylidene, carbonyl, thio orsulfonyl, Y₁ ˜Y₄ are individually hydrogen, lower alkyl radical, loweralkoxy radical, chlorine or bromine atom, and R is a divalent radicalselected from the group consisting of a monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected to eachother with a direct bond or a bridge member.

Another aspect of the invention is a polyimide resin compositioncomprising the aromatic bisimide compound and polyimide, for example, apolyimide resin composition comprising as requisite components 1 thebisimide compound represented by the above formula(1) and 2 polyimide,particularly the polyimide having recurring structural units of theformula(8): ##STR10## wherein A' is a divalent radical having theformula: ##STR11## wherein X is a direct bond, a divalent hydrocarbonradical having from 1 to 10 carbon atoms, hexafluorinatedisopropylidene, carbonyl, thio or sulfonyl, and Y₁ ˜Y₄ are individuallyhydrogen atom, lower alkyl radical, lower alkoxy radical, chlorine orbromine atom; or the formula: ##STR12## and R' is a tetravalent radicalhaving 2 or more carbon atoms and selected from the group consisting ofan aliphatic radical, alicyclic radical, monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected to eachother with a direct bond or a bridge member.

Following polyimide resin compositions are exemplified as preferredcombinations of the aromatic bisimide compound and polyimide.

(1) A polyimide resin composition wherein the polyimide has recurringstructural units represented by the formula(9): ##STR13## wherein R' isthe same as in the formula(8) and the aromatic bisimide compound isrepresented by the formula(10): ##STR14## wherein B is a direct bond, aradical selected from divalent hydrocarbon radical having from 1 to 10carbon atoms, hexafluorinated isopropylidene, carbonyl, thio, ether andsulfonyl, each nitrogen atom is individually para-, ortho- ormeta-located to B and R is a divalent radical selected from the groupconsisting of a monoaromatic radical, condensed polyaromatic radical,noncondensed aromatic radical connected to each other with a direct bondor a bridge member, and/or by the formula(2): ##STR15## wherein X, Y₁˜Y₄ and R are the same as above.

(2) A polyimide resin composition wherein the polyimide has recurringstructural units represented by the formula(11): ##STR16## wherein X isa direct bond, a divalent hydrocarbon radical having from 1 to 10 carbonatoms, hexafluorinated isopropylidene, carbonyl, thio or sulfonyl, Y₁˜Y₄ are individually hydrogen atom, lower alkyl radical, lower alkoxyradical, chlorine or bromine atom, and R' is a tetravalent radicalhaving 2 or more carbon atoms and selected from the group consisting ofan aliphatic radical, alicyclic radical, monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected to eachother with a direct bond or a bridge member; and the aromatic bisimidecompound is represented by the above formula(10) and/or the formula(2).

(3) A polyimide resin composition wherein the polyimide has recurringstructural units of the formula(9): ##STR17## wherein R' is the same asabove, and the aromatic bisimide compound is represented by theformula(3): ##STR18## wherein R is the same as above.

(4) A polyimide resin composition wherein the polyimide has recurringstructural units of the formula(11): ##STR19## wherein X, Y₁ ˜Y₄ and R'are the same as above, and the aromatic bisimide compound is representedby the formula(7): ##STR20## wherein X, Y₁ ˜Y₄ and R are the same asabove, the formula(12): ##STR21## wherein R is a divalent radicalselected from the group consisting of a monoaromatic radical, condensedpolyaromatic radical, and noncondensed aromatic radical connected toeach other with a direct bond or a bridge member, and two isopropylideneradicals are located each at para- or meta-position on a benzene ring,the formula(4): ##STR22## wherein R is the same as above, theformula(13): ##STR23## wherein R is a divalent radical selected from thegroup consisting of a monoaromatic radical, condensed polyaromaticradical and noncondensed aromatic radical connected to each other with adirect bond or a bridge member, and the two carbonyl radicals arelocated on meta- or para-position to the central ether bond, and theother two ether bonds on the outside are located on meta- orpara-position to said carbonyl radicals, respectively, the formula(14):##STR24## wherein Z is a radical selected from the group consisting ofcarbonyl or sulfonyl, and R is a divalent radical having 2 or morecarbon atoms and selected from the group consisting of an aliphaticradical, alicyclic radical, monoaromatic radical, condensed polyaromaticradical and noncondensed aromatic radical connected to each other with adirect bond or a bridge member, the formula(15): ##STR25## wherein R isa divalent radical selected from the group consisting of a monoaromaticradical, condensed polyaromatic radical and noncondensed aromaticradical connected to each other with a direct bond or a bridge member;the two carbonyl radicals are located at meta- or para-position on thecentral benzene ring; when the two carbonyl radicals are located onpara-position on the central benzene ring, both terminal nitrogen atomsare located at para- or meta-position to the ether linkages,respectively; and when the two carbonyl radicals are located onmeta-position on the central benzene ring, both terminal nitrogen atomsare located on para- or meta-position to the ether linkages,respectively, or the formula(16): ##STR26## wherein R is a divalentradical selected from the group consisting of a monoaromatic radical,condensed polyaromatic radical and noncondensed aromatic radicalconnected to each other with a direct bond or bridge member, and the twoisopropylidene radicals are located on para- or meta-position on thecentral benzene ring.

(5) A polyimide resin composition wherein the polyimide has recurringstructural units represented by the formula(17): ##STR27## wherein R' isa tetravalent radical having 2 or more carbon atoms and selected fromthe group consisting of an aliphatic radical, alicyclic radical,monoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember; and the aromatic bisimide compound is represented by the aboveformula(10), (2), (7), (12), (4), (13), (14), (15) or (16).

A further aspect of the invention is 1 a carbon fiber reinforcedpolyimide resin composition comprising a carbon fiber coated on thesurface with an aromatic bisimide compound, preferably a bisimidecompound represented by the above formula(2): ##STR28## wherein X, Y₁˜Y₄ and R are the same as above, and polyimide, particularly thepolyimide having recurring structural units represented by the aboveformula(11): ##STR29## wherein X, Y₁ ˜Y₄ and R' are the same as above,or the polyimide having recurring structural units represented by theformula(9): ##STR30## wherein R' is the same as above; or 2 a carbonfiber reinforced resin composition comprising a carbon fiber coated onthe surface with an aromatic bisimide compound represented by theformula(10): ##STR31## wherein B and R are the same as above, and thepolyimide having recurring structural units represented by theformula(11): ##STR32## wherein X, Y₁ ˜Y₄ and R' are the same as above.

The bisimide of the invention can simultaneously provide good heatresistance and processability for polyimide and is useful for heatresistant coatings, heat resistant adhesives, sizing agents of glassfiber and carbon fiber, and plasticizers of heat resistant resin.

Addition of the bisimide compound to polyimide resin can greatly reducemelt-viscosity of the resin and improve processability. Particularly,the polyimide resin composition comprising the bisimide compound of theinvention has remarkably improved processability.

The polyimide resin composition comprising the carbon fiber coated withthe bisimide compound of the invention has excellent mechanical strengthand can be widely used as a material for members of electric andelectronic devices, automotive trim, space and aeronautical equipmentand general instruments in industry. Therefore, the invention is veryvaluable in industry.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an IR absorption spectrum atlas of bisimide obtained inExample 1.

FIG. 2 is an IR absorption spectrum atlas of bisimide obtained inComparative Example 1.

FIG. 3 is an IR absorption spectrum atlas of bisimide obtained inExample 5.

FIG. 4 is an IR absorption spectrum atlas of bisimide obtained inExample 6.

FIG. 5 is an IR absorption spectrum of bisimide obtained in Example 8.

FIG. 6 is an IR absorption spectrum atlas of bisimide obtained inExample 10.

FIG. 7 is an IR absorption spectrum atlas of bisimide obtained inExample 12.

FIG. 8 is an IR absorption spectrum atlas of bisimide obtained inExample 14.

FIG. 9 is an IR absorption spectrum atlas of bisimide obtained inExample 16.

FIG. 10 is an IR absorption spectrum atlas of bisimide-3 obtained in theSynthesis Example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The bisimide compound of the invention is represented by the aboveformula(1) and practical compounds are respectively represented by theformulas(2), (3), (4), (5), (6) and (7).

The bisimide compound can be prepared by reacting a diamine compoundrepresented by the formula(1-a): ##STR33## wherein A is a divalentradical selected from the group consisting of radicals having theformulas: ##STR34## wherein X is a direct bond, a divalent hydrocarbonradical having from 1 to 10 carbon atoms, hexafluorinatedisopropylidene, carbonyl, thio or sulfonyl, and Y₁ ˜Y₄ are individuallyhydrogen atom, lower alkyl radical, lower alkoxy radical, chlorine orbromine atom, ##STR35## with a dicarboxylic acid anhydride representedby the formula(18): ##STR36## wherein R is a divalent radical selectedfrom the group consisting of a monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected eachother with a direct bond or a bridge member.

The diamine compounds used for preparing the bisimide compound of theinvention are represented by the formula(2-a): ##STR37## wherein X andY₁ ˜Y₄ are the same as in the formula(2).

Exemplary diamine compounds which are represented by the formula(2-a)include:

bis[4-(3-aminophenoxy)phenyl]methane,

1,1-bis[4-(3-aminophenoxy)phenyl]ethane,

2,2-bis[4-(3-aminophenoxy)phenyl]propane,

2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3-methylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)-3-methylphenyl]propane,

2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)phenyl]butane,

2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,

4,4'-bis(3-aminophenoxy)biphenyl,

4,4'-bis(3-aminophenoxy)-3-methylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dimethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,5-dimethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dichlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,5-dichlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetrachlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dibromobiphenyl,

4,4'-bis(3-aminophenoxy)-3,5-dibromobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetrabromobiphenyl,

bis[4-(3-aminophenoxy)phenyl]ketone,

bis[4-(3-aminophenoxy)phenyl]sulfide,

bis[4-(3-aminophenoxy)-3-methoxyphenyl]sulfide,

[4-(3-aminophenoxy)phenyl][4-(3-aminophenoxy)-3,5-dimethoxyphenyl]sulfide,

bis[4-(3-aminophenoxy)-3,5-dimethoxyphenyl]sulfide, and

bis[4-(3-aminophenoxy)phenyl]sulfone.

Other diamine compounds which can be used are

3,3'-diaminobenzophenone of the formula(3-a): ##STR38##bis[4-{4-(4-aminophenoxy)phenyl}phenyl]sulfone of the formula(4-a):##STR39## 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene of theformula(5-a): ##STR40## andbis[3-{4-(4-aminophenoxy)benzoyl}phenyl]ether of the formula(6-a):##STR41##

Further diamine compounds which can be used for preparing the bisimidecompound are represented by the formula(7-a): ##STR42## wherein X and Y₁˜Y₄ are the same as in the formula(7).

Exemplary diamine compounds which are represented by the formula(7-a)include:

1,1-bis[4-(4-aminophenoxy)phenyl]methane,

1,1-bis[4-(4-aminophenoxy)phenyl]ethane,

2,2-bis[4-(4-aminophenoxy)phenyl]propane,

2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane,

2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane,

2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(4-aminophenoxy)phenyl]butane,

2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,

4,4'-bis(4-aminophenoxy)biphenyl,

4,4'-bis(4-aminophenoxy)-3-methylbiphenyl,

4,4'-bis(4-aminophenoxy)-3,3'-dimethylbiphenyl,

4,4'-bis(4-aminophenoxy)-3,5-dimethylbiphenyl,

4,4'-bis(4-aminophenoxy)-3,3,5,5'-tetramethylbiphenyl,

4,4'-bis(4-aminophenoxy)-3,3'-dichlorobiphenyl,

4,4'-bis(4-aminophenoxy)-3,5-dichlorobiphenyl,

4,4'-bis(4-aminophenoxy)-3,3',5,5'-tetrachlorobiphenyl,

4,4'-bis(4-aminophenoxy)-3,3'-dibromobiphenyl,

4,4'-bis(4-aminophenoxy)-3,5-dibromobiphenyl,

4,4'-bis(4-aminophenoxy)-3,3',5,5'-tetrabromobiphenyl,

bis[4-(4-aminophenoxy)phenyl]ketone,

bis[4-(4-aminophenoxy)phenyl]sulfide,

bis[4-(4-aminophenoxy)-3-methoxyphenyl]sulfide,

[4-(4-aminophenoxy)phenyl][4-(4-aminophenoxy)-3,5-dimethoxyphenyl]sulfide,

bis[4-(4-aminophenoxy)-3,5-dimethoxyphenyl]sulfide, andbis[4-(4-aminophenoxy)phenyl]sulfone.

The diamine compounds enumerated above can be used singly or as amixture.

The aromatic dicarboxylic acid anhydrides used for the preparation ofbisimide compounds of the invention are represented by the formula(18)and include, for example, phthalic anhydride,

3-methylphthalic anhydride,

4-methylphthalic anhydride,

2,3-benzophenonedicarboxylic anhydride,

3,4-benzophenonedicarboxylic anhydride,

2,3-dicarboxyphenyl phenyl ether anhydride,

3,4-dicarboxyphenyl phenyl ether anhydride,

2,3-biphenyldicarboxylic anhydride,

3,4-biphenyldicarboxylic anhydride,

2,3-dicarboxyphenyl phenyl sulfone anhydride,

3,4-dicarboxyphenyl phenyl sulfone anhydride,

2,3-dicarboxyphenyl phenyl sulfide anhydride,

3,4-dicarboxyphenyl phenyl sulfide anhydride,

1,2-naphthalenedicarboxylic anhydride,

2,3-naphthalenedicarboxylic anhydride,

1,8-naphthalenedicarboxylic anhydride,

1,2-anthracenedicarboxylic anhydride,

2,3-anthracenedicarboxylic anhydride, and

1,9-anthracenedicarboxylic anhydride.

These anhydrides are used singly or as a mixture.

No particular restriction is imposed upon the reaction of the diaminewith the dicarboxylic acid anhydride. The reaction is preferably carriedout in organic solvents in particular.

Exemplary solvents used for the reaction include N,N-dimethylformamide,N, N-dimethylacetamide, N,N-diethylacetamide,N,N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone,1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam,1,2-dimethoxyethane, bis(2-methoxyethyl) ether,1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl]ether,tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethylsulfoxide, dimethyl sulfone, tetramethylurea, hexamethylphosphoramide,phenol, m-cresol, p-cresol, p-chlorophenol and anisole. These organicsolvents can be used singly or as a mixture.

Reaction temperature is usually 200° C. or less, preferably 50° C. orless. No particular limitation is placed on the reaction pressure. Thereaction can be satisfactorily carried out under atmospheric pressure.The reaction time varies depending upon the kind of solvents andreaction temperature. The reaction is usually carried out for sufficienttime to complete formation of bisamic acid which is the precursor of thebisimide compound of the invention. The reaction time of from 10 minutesto 24 hours is usually sufficient for the reaction.

The reaction can provide bisamic acids which correspond to the desiredbisimide compounds of the invention, that is, the bisamic acid havingthe formula(2-b): ##STR43## and corresponding to the bisimide compoundof the formula(2), the bisamic acid having the formula (3-b): ##STR44##and corresponding to the bisimide compound of the formula(3), thebisamic acid having the formula(4-b); ##STR45## and corresponding to thebisimide compound of the formula(4), the bisamic acid having theformula(5-b): ##STR46## and corresponding to the bisimide compound ofthe formula(5), the bisamic acid having the formula(6-b): ##STR47## andcorresponding to the bisimide compound of the formula(6), and thebisamic acid having the formula(7-b): ##STR48## and corresponding to thebisimide compound of the formula(7).

The bisamic acids thus obtained are heat-imidized at temperature of 80°to 400° C. or by chemically imidized with a imidizing agent such asacetic anhydride to give bisimide compounds having the formulas(1) to(7).

Alternatively, the above diamine compound and the above dicarboxylicacid anhydride are suspended or dissolved in an organic solvent, andformation and dehydrating imidization of the resulting bisamic acid canbe simultaneously carried out by heating from 50° to 400° C. to givecorresponding bisimide compounds.

The bisimide compounds having the formulas(2) and (7) which are preparedfrom the diamine compounds having the formulas (2-a) and (7-a) have amelting point of 290° C. or less. The bisimide compounds having theformula(3) which are prepared from the diamine compounds having theformula(3-a) have a melting point of 260° C. or less. Thus the bisimidecompounds obtained in the invention have lower melting points, can bemelt-processed with ease and have excellent processability as comparedwith high molecular weight polyimide. The bisimide compounds also havesolubility of 5% by weight or more in halogenated hydrocarbon solventssuch as dichloromethane, chloroform and carbon tetrachloride, and can beused in the form of solutions in these solvents.

The polyimide resin composition of the invention is a novel polyimideresin composition comprising the aromatic bisimide compound and thepolyimide as requisite components. The polyimide resin compositionprepared by using the novel bisimide compound having the formula(1) ofthe invention is preferred in particular.

No particular restriction is imposed upon the polyimide used in thepolyimide resin composition of the invention. Various kinds of polyimidecan be used and particularly preferred polyimide has recurringstructural units represented by the formula(8): ##STR49## wherein A' andR' are the same as above.

Useful kinds of polyimide include, for example, the polyimide havingrecurring structural units of the formula(9): ##STR50## wherein R' isthe same as above, the polyimide having recurring structural units ofthe formula(11): ##STR51## wherein X, Y₁ ˜Y₄ and R' are the same asabove, and the polyimide having recurring structural units of theformula(17): ##STR52## wherein R' is the same as above.

Consequently, representative embodiments of combination composed of thepolyimide resin component and the bisimide compound component include:

(1) the combination of the polyimide having recurring structural unitsof the formula(9): ##STR53## wherein R' is the same as above, with thebisimide compound having the formula(10): ##STR54## wherein B and R arethe same as above, and/or the formula(2): ##STR55## wherein X, Y₁ ˜Y₄and R are the same as above, (2) the combination of the polyimide havingrecurring structural units of the formula(11): ##STR56## wherein X, Y₁˜Y₄ and R' are the same as above, with the bisimide compound having theformula(10): ##STR57## wherein B and R are the same as above, and/or theformula(2): ##STR58## wherein X, Y₁ ˜Y₄ and R are the same as above, (3)the combination of the polyimide having recurring structural units ofthe formula(9): ##STR59## wherein R' is the same as above, with thebisimide compound having the formula(3): ##STR60## wherein R is the sameas above, (4)˜(17) the combination of the polyimide having recurringstructural units of the formula(11) or (17): ##STR61## wherein R' and Y₁˜Y₄ are the same as above, with the bisimide compound having theformula(7): ##STR62## wherein R and Y₁ ˜Y₄ are the same as above, theformula(12): ##STR63## wherein R is the same as above, the formula(4):##STR64## wherein R is the same as above, the formula(13): ##STR65##wherein R is the same as above, the formula(14): ##STR66## wherein R andZ are the same as above, the formula(15): ##STR67## wherein R is thesame as above, or the formula(16): ##STR68## wherein R is the same asabove.

The polyimide used in the composition of the invention can be preparedby reacting a diamine compound with a tetracarboxylic acid dianhydrideof the formula(19): ##STR69## wherein R' is a tetravalent radical having2 or more carbon atoms and selected from the group consisting of analiphatic radical, alicyclic radical, monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected to eachother with a direct bond or a bridge member, and successively bycarrying out dehydrating cyclization of the resultant polyamic acid.

The polyimide can be practically prepared with ease by the processesdisclosed in Japanese Laid-Open Patent Hei 2-022422, 2-133427 and2-229124.

Various diamine compounds can be used as raw materials for providing thedesired polyimide. For example, the following diamine compounds can beused.

In order to obtain polyimide having recurring structural units of theabove formula(9), 3,3-diaminobenzophenone is used.

Exemplary diamines which can provide the polyimide having recurringstructural units of the above formula(11) include

bis[4-(3-aminophenoxy)phenyl]methane,

1,1-bis[4-(3-aminophenoxy)phenyl]ethane,

2,2-bis[4-(3-aminophenoxy)phenyl]propane,

2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3-methylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)-3,5-dimethylbenzoyl]propane,

2,2-bis[4-(3-aminophenoxy)-3-methylphenyl]propane,

2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)phenyl]butane,

2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,

4,4'-bis(3-amoinophenoxy)biphenyl,

4,4'-bis(3-aminophenoxy)-3-methylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dimethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,5'-dimethylbiphenyl

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dichlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,5'-dichlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetrachlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dibromobiphenyl,

4,4'-bis(3-aminophenoxy)-3,5'-dibromobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetrabromobiphenyl,

bis[4-(3-aminophenoxy)phenyl]ketone,

bis[4-(3-aminophenoxy)phenyl]sulfide,

bis[4-(3-aminophenoxy)-3-methoxyphenyl]sulfide,

4-(3-aminophenoxy)phenyl][4-(3-aminophenoxy)-3,5-dimethoxyphenyl]sulfide,

bis[4-(3-aminophenoxy)-3,5-dimethoxyphenyl]sulfide, and

bis[4-(3-aminophenoxy)phenyl]sulfone.

These diamine compounds can be used singly or as a mixture.

In order to obtain the polyimide of the above formula(17),bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone is used.

Tetracarboxylic acid dianhydrides used in the invention and representedby the formula(19) include, for example,

ethylenetetracarboxylic dianhydride,

butanetetracarboxylic dianhydride,

cyclopentanetetracarboxylic dianhydride,

pyromellitic dianhydride,

1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride,

bis(2,3-dicarboxyphenyl)methane dianhydride,

bis(3,4-dicarboxyphenyl)methane dianhydride,

2,2-bis(3,4-dicarboxyphenyl)propane dianhydride,

2,2-bis(2,3-dicarboxyphenyl)propane dianhydride,

2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride,

2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride,

3,3',4,4'-benzophenonetetracarboxylic dianhydride,

2,2',3,3'-benzophenonetetracarboxylic dianhydride,

3,3',4,4'-biphenyltetracarboxylic dianhydride,

2,2',3,3'-biphenyltetracarboxylic dianhydride,

bis(3,4-dicarboxyphenyl)ether dianhydride,

bis(2,3-dicarboxyphenyl)ether dianhydride,

bis(3,4-dicarboxyphenyl)sulfone dianhydride,

4,4'-(p-phenylenedioxy)diphthalic dianhydride,

4,4'-(m-phenylenedioxy)diphthalic dianhydride,

2,3,6,7-naphthalenetetracarboxylic dianhydride,

1,4,5,8-naphthalenetetracarboxylic dianhydride,

1,2,5,6-naphthalenetetracarboxylic dianhydride,

1,2,3,4-benzenetetracarboxylic dianhydride,

3,4,9,10-perylenetetracarboxylic dianhydride,

2,3,6,7-anthracenetetracarboxylic dianhydride, and

1,2,7,8-phenanthrenetetracarboxylic dianhydride.

These tetracarboxylic acid dianhydrides can be used singly or as amixture.

In the preparation of the polyimide resin, a part of the above diaminecan be replaced with other aromatic diamines in the range giving noadverse effect on the good properties of the polyimide of the invention,for example, in the range of usually 50% by weight or less, preferably30% by weight or less for the amount of the above diamine.

In preparing the polyimide resin, it is preferred in view of improvingheat stability to carry out the reaction in the presence of dicarboxylicacid anhydride or monoamine.

Exemplary aromatic diamines which can replace the above diamines include

m-phenylenediamine,

o-phenylenediamine,

p-phenylenediamine,

m-aminobenzylamine,

p-aminobenzylamine,

bis(3-aminophenyl)ether,

(3-aminophenyl)(4-aminophenyl)ether,

bis(4-aminophenyl)ether,

bis(3-aminophenyl)sulfide,

(3-aminophenyl)(4-aminophenyl)sulfide,

bis(4-aminophenyl)sulfide,

bis(3-aminophenyl)sulfoxide,

(3-aminophenyl)(4-aminophenyl)sulfoxide,

bis(4-aminophenyl)sulfoxide,

bis(3-aminophenyl)sulfone,

(3-aminophenyl)(4-aminophenyl)sulfone,

bis(4-aminophenyl)sulfone,

3,4'-diaminobenzophenone,

4,4'-diaminobenzophenone,

bis[4-(4-aminophenoxy)phenyl]methane,

1,1-bis[4-(4-aminophenoxy)phenyl]ethane,

1,2-bis[4-(4-aminophenoxy)phenyl]ethane,

2,2-bis[4-(4-aminophenoxy)phenyl]propane,

2,2-bis[4-(4-aminophenoxy)phenyl]butane,

2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,

1,3-bis(3-aminophenoxy)benzene,

1,3-bis(4-aminophenoxy)benzene,

1,4-bis(3-aminophenoxy)benzene,

1,4-bis(4-aminophenoxy)benzene,

4,4'-bis(4-aminophenoxy)biphenyl,

bis[4-(4-aminophenoxy)phenyl]ketone,

bis[4-(4-aminophenoxy)phenyl]sulfide,

bis[4-(4-aminophenoxy)phenyl]sulfoxide,

bis[4-(4-aminophenoxy)phenyl]sulfone,

bis[4-(3-aminophenoxy)phenyl]ether,

bis[4-(4-aminophenoxy)phenyl]ether,

1,4-bis[4-(3-aminophenoxy)benzoyl]benzene,

1,3-bis[4-(3-aminophenoxy)benzoyl]benzene,

bis[4-(3-aminophenoxy)phenyl]methane,

1,1-bis[4-(3-aminophenoxy)phenyl]ethane,

2,2-bis[4-(3-aminophenoxy)phenyl]propane,

2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3-methylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)-3-methylphenyl]propane,

2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,

2,2-bis[4-(3-aminophenoxy)phenyl]butane,

2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,

4,4'-bis(3-aminophenoxy)biphenyl,

4,4'-bis(3-aminophenoxy)-3-methylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dimethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,5'-dimethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dichlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,5'-dichlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetrachlorobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3'-dibromobiphenyl,

4,4'-bis(3-aminophenoxy)-3,5'-dibromobiphenyl,

4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetrabromobiphenyl,

bis[4-(3-aminophenoxy)phenyl]ketone,

bis[4-(3-aminophenoxy)phenyl]sulfide,

bis[4-(3-aminophenoxy)-3-methoxyphenyl]sulfide,

[4-(3-aminophenoxy)phenyl][4-(3-aminophenoxy)-3,5-dimethoxyphenyl]sulfide,

bis[4-(3-aminophenoxy)-3,5-dimethoxyphenyl]sulfide, and

bis[4-(3-aminophenoxy)phenyl]sulfone.

The polyimide resin powder of the above formula(9) has an inherentviscosity in the range of usually from 0.10 to 1.50 dl/g, preferablyfrom 0.30 to 1.22 dl/g. The viscosity lower than 0.10 dl/g cannotprovide the desired mechanical strengths. On the other hand, theviscosity higher than 1.50 dl/g leads to high melt viscosity and poorprocessability.

The polyimide resin powder of the above formula(11) has an inherentviscosity in the range of usually from 0.10 to 1.50 dl/g, preferablyfrom 0.25 to 1.22 dl/g. The viscosity lower than 0.10 dl/g cannotprovide the desired mechanical strengths. On the other hand, theviscosity higher than 1.50 dl/g leads to high melt viscosity and poorprocessability.

The inherent viscosity indicated herein is measured at 35° C. in asolution containing 0.5 g of the polyimide resin in 100 ml of a solventmixture of p-chlorophenol/phenol in a ratio of 90/10 by weight.

The aromatic bisimide compounds which can be used as fluidizationaccelerators in the composition of the invention include the compound ofthe formula(1), the compounds illustrated by the lower concept, that is,the formula(2), (3), (4), (5), (6) or (7), and other various aromaticbisimide compounds.

In the aromatic bisimide compounds which are used for a component of thecomposition of the invention, the bisimide compound of the invention canbe prepared by the above preparation process and the processes describedin detail in the examples.

Other bisimide compounds used for the composition of the invention, thatis, the bisimide compounds of the formulas(10), (13), (14), (15) and(17) are prepared by the following processes.

The bisimide compound represented by the formula(10) and/or theformula(2) can be prepared with ease by reacting the diamine representedby the formula(10-a): ##STR70## wherein B is the same as in theformula(10), and/or the diamine represented by the formula(2-a), withthe aromatic dicarboxylic acid anhydride represented by the formula(19)and successively by carrying out dehydrating cyclization of theresultant bisamic acid,

Useful diamines represented by the formula(10-a) include, for example,3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether,4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide,3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide,3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone,4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone,3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone,3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane,4,4'-diaminodiphenylmethane, 1,1-bis(3-aminophenyl)ethane,1,1-bis(4-aminophenyl)ethane, 1,1-(3-aminophenyl)(4-aminophenyl)ethane,2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane,2,2-(3-aminophenyl)(4-aminophenyl)propane,2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane,2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane and2,2-(3-aminophenyl)(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane. Thesediamines can be used singly or as a mixture.

The diamines of the formula(2-a) which can be used are compoundspractically enumerated above. These diamines can be used singly or as amixture.

The diamines of the formula(10-a) can be previously mixed with thediamines of the formula(2-a) in the preparation of the bisimidecompound.

The aromatic dicarboxylic acid anhydrides which can be used arecompounds represented by the formula(18) and include, for example,phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalicanhydride, 2,3-benzophenonedicarboxylic anhydride,3,4-benzophenonedicarboxylic anhydride, 2,3-dicarboxyphenyl phenyl etheranhydride, 3,4-dicarboxyphenyl phenyl ether anhydride,3,4-biphenyldicarboxylic anhydride, 2,3-biphenyldicarboxylic anhydride,2,3-dicarboxyphenyl phenyl sulfone anhydride, 3,4-dicarboxyphenyl phenylsulfone anhydride, 2,3-dicarboxyphenyl phenyl sulfide anhydride,3,4-dicarboxyphenyl phenyl sulfide anhydride,1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylicanhydride, 1,8-naphthalenedicarboxylic anhydride,1,2-anthracenedicarboxylic anhydride, 2,3-anthracenedicarboxylicanhydride and 1,9-anthracenedicarboxylic anhydride. These compound canbe used singly or as a mixture.

The diamine compounds used for preparing the other bisimide compounds ofthe formula(12) are represented by the formula(12-a): ##STR71## andinclude, for example, 1,3-bis(4-amino-α,α-dimethylaminobenzyl) benzeneand 1,4-bis(4-amino-α,α-dimethylaminobenzyl)benzene.

Exemplary diamine compounds used for preparing the bisimide compounds ofthe formula(13) are represented by the formuta(13-a): ##STR72## andinclude bis[3-{4-(4-aminophenoxy)benzoyl}phenyl]ether,bis[4-{4-(4-aminophenoxy)benzoyl}phenyl]ether,bis[4-{3-(4-aminophenoxy)benzoyl}phenyl]ether andbis[3-{3-(4-aminophenoxy)benzoyl}phenyl]ether.

Representative diamine compounds used for preparing the bisimidecompounds of the formula(14) are represented by the formula(14-a):##STR73## wherein Z is the same as above, and include4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone andbis[4-{4-(4-amino-α,α-dimethylbenzyl)phenoxy}phenyl]sulfone.

Useful diamine compounds for use in the preparation of the bisimidecompounds of the formula(15) are represented by the formula(15-a):##STR74## and include, for example,1,4-bis[4-(3-aminophenoxy)benzoyl]benzene,1,4-bis[4-(4-aminophenoxy)benzoyl]benzene,1,3-bis[4-(3-aminophenoxy)benzoyl]benzene and1,3-bis[3-(3-aminophenoxy)benzoyl]benzene.

The diamine compounds which can be used for the preparation of thebisimide compounds of the formula(16) are represented by theformula(16-a): ##STR75## and include, for example,1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene and1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene.

The aromatic dicarboxylic acid anhydride are represented by the aboveformula(18) and any of the compounds practically enumerated can be used.

No particular restriction is imposed upon the method for reacting thediamine compound with the dicarboxylic acid anhydride. Known methods canbe arbitrarily employed. The method for preparing the above bisimidecompound of the invention can also be employed.

In processing the resin composition of the invention, the aromaticbisimide compound is used in the range of from 0.5 to 100 parts byweight for 100 parts by weight of the polyimide. The effect of thearomatic bisimide compound as a fluidization accelerator can be observedin a relatively small amount. Even an amount of 0.5 part by weight ofthe bisimide compound for 100 parts by weight of the polyimide is alsoeffective. An amount of 1 part by weight or more is particularlyeffective. However, an amount of the aromatic bisimide compoundexceeding 100 parts by weight tends to impair the mechanical strength ofthe resulting polyimide resin composition, and the range of 100 parts byweight or less is thus preferred.

Preparation of the polyimide resin composition of the invention can becarried out by usually known methods. For example, following methods arepreferred.

1. Polyimide resin powder and the aromatic bisimide compound is premixedinto powder with a mortar, Henschel mixer, drum blender, tumblingblender, ball mill or ribbon blender.

2. Polyimide resin powder is previously dissolved or suspended in anorganic solvent, the aromatic bisimide compound is added to theresulting solution or suspension and uniformly suspended or dissolved,and thereafter the solvent is removed to obtain powder.

3. An aromatic bisimide compound and/or its aromatic bisamic acidprecursor are dissolved or suspended in an organic solvent solution ofpolyamic acid which is the precursor of the polyimide and successivelyheat-treated at 100° to 400° C. or chemically imidized with a usualimidizing agent. Solvent is removed from the resulting mixture to obtainthe powder.

The resin composition thus obtained in the form of powder can be used asintact for various processes such as injection molding, compressionmolding, transfer molding and extrusion. The powder is more preferablyprocessed after melt-kneading.

Melt-kneading can be carried out with equipment for melt-kneading commonrubbers or plastics, for example, hot rolls, Banbury mixer, Brabenderand extruder. Melt-kneading temperature is usually set higher thanmelting temperature of the blending system and lower than decompositioninitiating temperature of the system. The temperature is usually from280° to 420° C., preferably from 300° to 400° C.

Injection molding and extrusion forming which can perform uniformmelt-kneading and have high productivity are suitable for processing theresin composition of the invention. However, transfer molding,compression molding, sinter molding, and other processing methods canalso be applied.

Prepreg for composite materials can be prepared by melt-impregnatingcarbon fiber or glass fiber with the above uniformly kneaded resincomposition or by impregnating various fibers with a uniform solution ordispersion of the polyimide resin and aromatic. bisimide compound, andsuccessively by removing the solvent.

Various kinds of additives can be incorporated with the resincomposition of the invention.

Useful additives include, for example, solid lubricants such asmolybdenum disulfide, graphite, boron nitride, lead monoxide and leadpowder; reinforcements such as glass fiber, carbon fiber, aromaticpolyimide, silicon carbide fiber, potassium titanate fiber and glassbeads; and other common auxiliary agents such as antioxidants, heatstabilizers, ultraviolet absorbers, flame retardants, antistatic agents,lubricants and colorants. These additives can be used singly or as amixture in an amount giving no adverse effect on the properties of theresin composition of the invention.

A further embodiment of the invention is a polyimide resin compositioncomprising the polyimide resin and carbon fiber coated on the surfacewith the aromatic bisimide compound. As result of more detailedinvestigation by the inventors, the invention is a polyimide resincomposition comprising a carbon fiber coated as a collecting agent onthe surface with a bisimide compound represented by the aboveformula(10): ##STR76## wherein B and R are the same as above, and apolyimide having recurring structural units represented by theformula(11): ##STR77## wherein X, Y₁ ˜Y₂ and R' are the same as above;or a polyimide resin composition comprising a carbon fiber coated as acollecting agent on the surface with a bisimide compound represented bythe formula(2): ##STR78## wherein X, Y₁ ˜Y₄ and R' are the same asabove, and a polyimide having recurring structural units represented bythe formula(11): ##STR79## wherein X, Y₁ ˜Y₄ and R' are the same asabove, or a polyimide having recurring structural units represented bythe formula(9): ##STR80## wherein R' is the same as above.

The bisimide compound which is applied to the carbon fiber in theinvention is represented by the formula(10) or the formula(2) which isobtained by reacting the diamine with the dicarboxylic acid anhydride asdescribed above.

The polyimide resin which can be used for the composition of theinvention has recurring structural units represented by the formula(11):##STR81## wherein X, Y₁ ˜Y₄ and R' are the same as above, or recurringstructural units represented by the formula(9): ##STR82## wherein R' isthe same as above.

When the bisimide compound of the formula(15) is applied to the carbonfiber, the polyimide having recurring structural units of theformula(11) is preferably used in particular. When the bisimide compoundof the formula(2) is applied to the carbon fiber, the polyimides havingrecurring structural units of the formula(11) and recurring structuralunits of the formula(9) are preferably used.

The polyimide used for the composition of the invention and the bisimidecompound applied to the carbon fiber can be prepared by using the sameor different diamine as a raw material component. That is, X and Y₁ ˜Y₄in the formula(11) can be the same as or different from X and Y₁ ˜Y₄ inthe formula(2).

Exemplary carbon fibers which can be coated with the bisimide compoundinclude acrylic carbon fiber, rayon-based carbon fiber, lignin-basedcarbon fiber and pitch-based carbon fiber. Acrylic carbon fiber is mostpreferably used in the invention because of its highest fiber strength.

The form of carbon fiber can be any kind such as chopped strand, rovingand woven fabric. The surface of carbon fiber is more preferablyoxidation-treated in advance by ozone or electrolytic oxidation.

In order to apply the bisimide compound to carbon fiber, the bisimidecompound is dissolved in a solvent such as dichloromethane, chloroform,1,2-dichloroethane, 1,1,2,2-tetrachloroethane, dimethyl sulfoxide,N,N-dimethylacetamide, N-methyl-pyrrolidone, methyl ethyl ketone,1,1,2-trichloroethane, m-cresol, p-cresol, o-cresol, p-chlorophenol,o-chlorophenol, m-chlorophenol and phenol.

Carbon fiber is immersed in the resulting bisimide solution andsuccessively dried by removing the solvent to obtain the bisimide coatedcarbon fiber.

The bisimide compound of the formula(2) which can be used in theinvention has a melting point of 290° C. or less and the bisimidecompound of the formula(15) has a melting point of 350° C. or less. Bothbisimide compounds can be melt processed and thus the bisimide coatedcarbon fiber can also be prepared by a melt-immersion method.

The coating amount of the bisimide compound on the carbon fiber ispreferably in the range of from 0.1 to 10 parts by weight, morepreferably from 0.5 to 9 parts by weight, most preferably from 1 to 8parts by weight for 100 parts by weight of the coated carbon fiber.

Various methods can be used for mixing the bisimide coated carbon fiberthus obtained and the polyimide resin. For example, the coated carbonfiber is cut into a length of 3 to 8 mm. The cut fiber thus obtained andthe polyimide resin can be separately fed to an extruder and melt-mixed,or are previously blended in a mixer such as a Henschel mixer, supermixer and ribbon blender, and successively fed to the extruder.Alternatively, the coated carbon fiber roving can be directly fed to theextruder and mixed with the polyimide resin.

The amount of the bisimide coated carbon fiber and the polyimide resinmatrix in the composition of the invention is from 5 to 50 parts byweight, preferably from 10 to 50 parts by weight of the carbon fiber andfrom 95 to 50 parts by weight, preferably from 90 to 50 parts by weightof the polyimide resin. When the amount of the carbon fiber is less than5 parts by weight, increase of tensile strength of the resulting resincomposition is unfavorably small. When the amount of the carbon fiberexceeds 50 parts by weight, uniform mixing of molten resin compositionbecomes difficult and melt-flowability is severely decreased to impairprocessability such as injection molding ability.

Other additives can be incorporated, if desired, with the composition ofthe invention in addition to the polyimide resin and the bisimide coatedcarbon fiber. Exemplary additives include talc, calcium carbonate, mica,glass beads and other fillers, glass fiber, potassium titanate fiber,aramide fiber, ceramic fiber and other fibrous reinforcements,stabilizers and colorants. These additives can be used in an amountgiving no adverse effect on the quality and performance of thecomposition of the invention.

As mentioned above, the resin composition of the invention comprisingthe bisimide coated carbon fiber and the polyimide resin can beprocessed into desired articles by injection molding, extrusion forming,transfer molding, compression molding and other known processingmethods. The resin composition of the invention thus processed hasexcellent mechanical strength, at high temperatures in particular, andis hence used for mechanical members and automotive parts which requirehigh mechanical strength at high temperatures, for example, gear, cam,bushing, pulley and sleeve, and also for members of internal combustionengines, for example, gas exhausting parts for a silencer such as animpeller and manifold of an integrated centrifugal compressor, valveguide, valve stem, piston skirt, oil pan, front cover and locker cover.

The carbon fiber reinforced polyimide resin composition of the inventionis usually used in the form of pellets which can be handled with ease.Molded articles are prepared by injection molding. The pellets areprepared by kneading and extruding the polyimide resin and the carbonfiber strand with a known single or twin screw extruder and successivelyby cutting the resulting strand of the composition.

Injection molding of the pellets thus obtained is carried out with acommon injection molding machine at a cylinder temperature of 360° to420° C. and a mold temperature of 160° to 210° C., preferably 180° to200° C. Complex shaped members of internal combustion engines such as animpeller of an integrated centrifugal compressor can also be preparedwith ease.

The present invention will hereinafter be illustrated in detail by wayof examples and comparative examples.

EXAMPLE 1

To a reaction vessel equipped with a stirrer, reflux condenser and anitrogen inlet tube, 368 g(1.0 mole) of 4,4'-bis(3-aminophenoxy)biphenyl and 5.215 g of N,N-dimethylacetamide were charged, and 311g(2.1 moles) of phthalic anhydride was added at room temperature andstirred for 2 hours.

Successively, 404 g(4 moles) of triethyl amine and 306 g(3 moles) ofacetic anhydride were added dropwise to the resulting solution andstirred for 2 hours. The slurry thus formed was poured into methanol.The precipitate was filtered, dispersed in methanol, and filtered again.The procedures were repeated again. The filtered precipitate was driedat 150° C. for 2 hours to obtain 475 g of white powder. The powder had amelting point of 286° C. by DSC, a melt-initiation temperature of about280° C. and good melt processability.

Results of elemental analysis were as follows.

    ______________________________________                                        Elemental analysis (C.sub.40 H.sub.24 N.sub.2 O.sub.6)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             76.40       3.82   4.46                                          Found (%)    76.27       3.80   4.49                                          ______________________________________                                    

An IR-absorption spectrum atlas is illustrated in FIG. 1. In thespectrum atlas, characteristic absorption band of imide at around 1780cm⁻¹ and 1720 cm⁻¹ and characteristic absorption band of ether at around1240 cm⁻¹ were remarkably found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained was bisimide having the structure of the formula(20): ##STR83##

The bisimide had solubility of 5% by weight or more in dichloromethane,chloroform and carbon tetrachloride, and also had good processability.

EXAMPLES 2˜4

Each bisimide powder was prepared by carrying out the same procedures asconducted in Example 1 except that diamines were used as illustrated inTable 1.

The melting point and results of elemental analysis on the powder thusobtained are illustrated in Table 1.

Any bisimide compound had solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

                  TABLE 1                                                         ______________________________________                                                Diamine               Melting                                         Example Amount g (mole)       point (°C.)                              ______________________________________                                        2       bis[4-(3-aminophenoxy)phenyl]                                                                       270                                                     ketone                                                                        396.5 (1.0)                                                           3       bis[4-(3-aminophenoxy)phenyl]-                                                                      230                                                     sulfide                                                                       400.5 (1.0)                                                           4       2,2'-bis[4-(3-aminophenoxy)phenyl]                                                                  250                                                     propane                                                                       410.5 (1.0)                                                           ______________________________________                                        Elemental analysis (%)                                                                    C      H          N    S                                          ______________________________________                                        Calculated  75.00  3.66       4.27 0                                          Found       74.85  3.60       4.31 0                                          Calculated  72.70  3.64       4.24   4.85                                     Found       72.56  3.60       4.34   4.88                                     Calculated  77.01  4.48       4.18 0                                          Found       76.92  4.42       4.21 0                                          ______________________________________                                    

Comparative Example 1

The same procedures were carried out as conducted in Example 1 exceptthat 368 g of 4,4'-bis(3-aminophenoxy)biphenyl was replaced by 195.6g(2.1 moles) of aniline and 311 g of phthalic anhydride was replaced by218.1 g(2.1 moles) of pyromellitic dianhydride. Light yellow powder thusobtained was 360 g.

Results on the elemental analysis of the powder are as follows.

    ______________________________________                                        Elemental analysis (C.sub.22 H.sub.12 N.sub.2 O.sub.4)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             71.74       3.26   7.61                                          Found (%)    71.70       3.20   7.65                                          ______________________________________                                    

An IR absorption spectrum of the powder is illustrated in FIG. 2. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹, and the characteristic absorption band of etheraround 1240 cm⁻¹ were remarkably found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained was bisimide having the structure of the formula(21): ##STR84##

The bisimide had solubility of 0.01% by weight or less indichloromethane, chloroform and carbon tetrachloride, was poor inprocessability and had a very high melting point of 442° C.

EXAMPLE 5

To the same reaction vessel as used in Example 1, 212 g(1.0 mole) of3,3'-diaminobenzophenone and 5215 g of N,N-dimethylacetamide werecharged and 311 g(2.1 moles) of phthalic anhydride was added at roomtemperature and stirred for 2 hours.

Successively, 404 g(4 moles) of triethylamine and 306 g(3 moles) ofacetic anhydride were added dropwise to the resultant solution andstirred for 2 hours at room temperature. The reaction mixture was pouredinto methanol. The precipitate was filtered, dispersed in methanol andfiltered again. The procedures were repeated again. The precipitate thusobtained was dried at 150° C. for 2 hours. White powder thus obtainedwas 453 g, had a melting point of 240° C. and a melt initiation point ofabout 230 ° C., and was good in melt processability.

Results on the elemental analysis are as follows.

    ______________________________________                                        Elemental analysis (C.sub.29 H.sub.16 N.sub.2 O.sub.5)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             73.73       3.39   5.93                                          Found (%)    73.61       3.30   5.96                                          ______________________________________                                    

An IR absorption spectrum of the powder is illustrated in FIG. 3. In thespectrum atlas, characteristic absorption band of imide around 1780 cm⁻¹and 1720 cm⁻¹ was remarkably observed.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus obtainedwas bisimide having the structure of the formula(22): ##STR85##

The bisimide had solubility of 5% by weight or more in dichloromethane,chloroform and carbon tetrachloride, and also had good processability.

EXAMPLE 6

To the same reaction vessel as used in Example 1, 616.7 g(1.0 mole) ofbis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone and 1850 g of m-cresylicacid were charged, and 325.6 g(2.2 moles) of phthalic anhydride wasadded at room temperature. The mixture was heated to 140° C. and reactedfor 2 hours.

Successively, the reaction mixture was poured into methanol andresulting precipitate was filtered, washed 3 times with methanol anddried at 150° C. for 2 hours to obtain 873.7 g(96.4% yield) of whitepowder having a melting point of 217° C.

Following results were obtained on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.52 H.sub.32 N.sub.2 S.sub.1 O.sub.10)                           C    H          N     S                                           ______________________________________                                        Calculated (%)                                                                              71.2   3.6        3.2 3.6                                       Found (%)     70.8   3.7        3.3 3.6                                       ______________________________________                                    

An IR absorption spectrum of the powder is illustrated in FIG. 4. In thespectrum atlas, the characteristic absorption spectrum of imide around1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus obtainedwas bisimide having the structure of the formula(23): ##STR86##

The bisimide thus obtained had solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

EXAMPLE 7

The same procedures as conducted in Example 6 were carried out exceptthat 325.6 g(2.2 moles) of phthalic anhydride was replaced by 436 g(2.2moles) of 2,3-naphthalenedicarboxylic anhydride. White powder thusobtained was 938 g(96% yield) and had a melting point of 218° C.Following results were obtained on the elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.60 H.sub.36 N.sub.2 S.sub.1 O.sub.10)                           C    H          N     S                                           ______________________________________                                        Calculated (%)                                                                              73.8   3.7        2.9 3.3                                       Found (%)     73.6   3.5        3.0 3.3                                       ______________________________________                                    

In an IR absorption spectrum atlas, characteristic absorption band ofimide around 1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found.

According to the Identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus obtainedwas bisimide having the structure of the formula(24): ##STR87##

The bisimide had solubility of 5% by weight or more in dichloromethane,chloroform and carbon tetrachloride and also had good processability.

EXAMPLE 8

To the same reaction vessel as used in Example 1, 344.5 g(1.0 mole) of1,3-bis(4-amino-α,α-dimethylbenzyl)benzene and 3426 g of m-cresylic acidwere charged and 325.6 g(2.2 moles) of phthalic anhydride was added atroom temperature. The mixture was heated to 140 ° C. and reacted for 2hours. Successively, the reaction mixture was poured into methanol. Theprecipitate was filtered, washed several times with methanol and driedat 100° C. for 16 hours under reduced pressure. White powder thusobtained was 590.6 g(97.7% yield) and had a melting point of 240° C.Following results were obtained on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.40 H.sub.32 N.sub.2 O.sub.4)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             79.47       5.30   4.64                                          Found (%)    79.73       5.43   4.60                                          ______________________________________                                    

An IR absorption spectrum atlas is illustrated in FIG. 5. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the other hand, thecharacteristic absorption band of amic acid around 1550 cm⁻¹, thecharacteristic absorption band of diamine around 3200˜3400 cm⁻¹, and thecharacteristic absorption band of acid anhydride around L850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus formed isbisimide having the structure of the formula(25): ##STR88##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride, and also had goodprocessability.

EXAMPLE 9

The same procedures as conducted in Example 8 were carried out exceptthat 325.6 g(2.2 moles) of phthalic anhydride was replaced by 436 g(2.2moles) of 2,3-naphthalenedicarboxylic anhydride. White powder obtainedwas 687 g(97% yield), had a melting point of 241° C., and gave followingresults on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.48 H.sub.40 N.sub.2 O.sub.4)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             81.36       5.65   3.95                                          Found (%)    81.05       5.58   3.94                                          ______________________________________                                    

In an IR absorption spectrum atlas, characteristic absorption band ofimide around 1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the otherhand, characteristic absorption band of amic acid around 1550 cm⁻¹,characteristic absorption band of diamine around 3200˜3400 cm⁻¹, andcharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained is bisimide having the structure of the formula(26): ##STR89##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

EXAMPLE 10

To the same reaction vessel as used in Example 1, 592.7 g(1.0 mole) ofbis[3-{4-(4-aminophenoxy)benzoyl}phenyl]ether and 4832 g of m-cresylicacid were charged and 325.6 g(2.2 moles) of phthalic anhydride was addedat room temperature. The mixture was heated to 140° C. and reacted for 2hours.

Successively, the reaction mixture was poured into methanol. Theprecipitate formed was filtered, washed several times with methanol anddried at 100° C. for 16 hours under reduced pressure.

Yellow powder thus obtained was 820.3 g(96.2% yield). The powder had amelting point of 202° C.

Following results were obtained on the elemental analysis of the powder.

    ______________________________________                                        Elemental analysis (C.sub.54 H.sub.32 N.sub.2 O.sub.9)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             76.06       3.76   3.29                                          Found (%)    76.18       3.85   3.42                                          ______________________________________                                    

An IR absorption spectrum atlas is illustrated in FIG. 6. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the other hand, thecharacteristic absorption band of amic acid around 1550 cm⁻¹, thecharacteristic absorption band of diamine around 3200˜3400 cm⁻¹, and thecharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus formed isbisimide having the structure of the formula(27): ##STR90##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride, and also had goodprocessability.

EXAMPLE 11

The same procedures as conducted in Example 10 were carried out exceptthat 325.6 g(2.2 moles) of phthalic anhydride was replaced by 436 g(2.2moles) of 2,3-naphthalenedicarboxylic anhydride. Yellow powder obtainedwas 909 g(95% yield), had a melting point of 176° C., and gave followingresults on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.62 H.sub.32 N.sub.2 O.sub.9)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             77.82       3.35   2.93                                          Found (%)    77.68       3.45   3.02                                          ______________________________________                                    

In an IR absorption spectrum atlas, characteristic absorption band ofimide around 1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the otherhand, characteristic absorption band of amic acid around 1550 cm⁻¹,characteristic absorption band of diamine around 3200˜3400 cm⁻¹, andcharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained is bisimide having the structure of the formula(28): ##STR91##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

EXAMPLE 12

To the same reaction vessel as used in Example 1, 368.4 g(1.0 mole) of4,4'-bis(4-aminophenoxy)biphenyl and 3561 g of m-cresol were charged and325.6 g(2.2 moles) of phthalic anhydride was added at room temperature.The mixture was heated to 140° C. and reacted for 2 hours.

Successively, the reaction mixture was poured into methanol. Theprecipitate formed was filtered, washed several times with methanol anddried at 100° C. for 16 hours under reduced pressure.

Yellow powder thus obtained was 600.1 g(95.5% yield). The powder had amelting point of 292° C.

Following results were obtained on the elemental analysis of the powder.

    ______________________________________                                        Elemental analysis (C.sub.40 H.sub.24 N.sub.2 O.sub.6)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             76.40       3.82   4.46                                          Found (%)    76.72       3.92   4.51                                          ______________________________________                                    

An IR absorption spectrum atlas is illustrated in FIG. 7. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the other hand, thecharacteristic absorption band of amic acid around 1550 cm⁻¹, thecharacteristic absorption band of diamine around 3200˜3400 cm⁻¹, and thecharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the Identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus formed isbisimide having the structure of the formula(29): ##STR92##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride, and also had goodprocessability.

EXAMPLE 13

The same procedures as conducted in Example 12 were carried out exceptthat 325.6 g(2.2 moles) of phthalic anhydride was replaced by 436 g(2.2moles)of 2,3-naphthalenedicarboxylic anhydride. Light yellow powderobtained was 696 g(95% yield), had a melting point of 293°0 C., and gavefollowing results on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.48 H.sub.32 N.sub.2 O.sub.6)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             78.69       4.37   3.83                                          Found (%)    78.70       4.28   3.61                                          ______________________________________                                    

In an IR absorption spectrum atlas, characteristic absorption band ofimide around 1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found.

On the other hand, characteristic absorption band of amic acid around1550 cm⁻¹, characteristic absorption band of diamine around 3200˜3400cm⁻¹, and characteristic absorption band of acid anhydride around 1850cm⁻¹ were not found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained is bisimide having the structure of the formula(30): ##STR93##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

EXAMPLE 14

To the same reaction vessel as used in Example 1, 410.5 g(1 mole) of2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 3800 g of m-cresol werecharged and 325.6 g(2.2 moles) of phthalic anhydride was added at roomtemperature. The mixture was heated to 140° C. and reacted for 2 hours.

Successively, the reaction mixture was poured into methanol. Theprecipitate formed was filtered, washed several times with methanol anddried at 100° C. for 16 hours under reduced pressure.

Light yellow powder thus obtained was 612.8 g(91.4% yield). The powderhad a melting point of 218° C.

Following results were obtained on the elemental analysis of the powder.

    ______________________________________                                        Elementary analysis (C.sub.43 H.sub.30 N.sub.2 O.sub.6)                                  C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             77.01       4.48   4.18                                          Found (%)    76.84       4.55   4.26                                          ______________________________________                                    

An IR absorption spectrum atlas is illustrated in FIG. 8. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the other hand, thecharacteristic absorption band of amic acid around 1550 cm⁻¹, thecharacteristic absorption band of diamine around 3200˜3400 cm⁻¹, and thecharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus formed isbisimide having the structure of the formula(31): ##STR94##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

EXAMPLE 15

The same procedures as conducted in Example 14 were carried out exceptthat 325.6 g(2.2 moles) of phthalic anhydride was replaced by 436 g(2.2moles) of 2,3-naphthalenedicarboxylic anhydride. White powder obtainedwas 697 g(90% yield), had a melting point of 219° C., and gave followingresults on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.51 H.sub.38 N.sub.2 O.sub.6)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             79.07       4.91   3.62                                          Found (%)    78.72       5.05   3.54                                          ______________________________________                                    

In an IR absorption spectrum atlas, characteristic absorption band ofimide around 1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the otherhand, characteristic absorption band of amic acid around 1550 cm⁻¹,characteristic absorption band of diamine around 3200˜3400 cm⁻¹, andcharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained is bisimide having the structure of the formula(32): ##STR95##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride and also had goodprocessability.

EXAMPLE 16

To the same reaction vessel as used in Example 1, 400.5 g(1.0 mole) ofbis[4-(4-aminophenoxy)phenyl]sulfide and 3743 g of m-cresol were chargedand 325.6 g(2.2 moles) of phthalic anhydride was added at roomtemperature. The mixture was heated to 140° C. and reacted for 2 hours.

Successively, the reaction mixture was poured into methanol. Theprecipitate formed was filtered, washed several times with methanol anddried at 100° C. for 16 hours under reduced pressure.

White powder thus obtained was 612.9 g(92.8% yield). The powder had amelting point of 252° C.

Following results were obtained on the elemental analysis of the powder.

    ______________________________________                                        Elemental analysis (C.sub.40 H.sub.24 N.sub.2 O.sub.6 S)                                  C    H         N      S                                           ______________________________________                                        Calculated (%)                                                                              72.70  3.64      4.24 4.85                                      Found (%)     72.66  3.73      4.26 4.99                                      ______________________________________                                    

An IR absorption spectrum atlas is illustrated in FIG. 9. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the other hand, thecharacteristic absorption band of amic acid around 1550 cm⁻¹, thecharacteristic absorption band of diamine around 3200˜3400 cm⁻¹, and thecharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus formed isbisimide having the structure of the formula(33): ##STR96##

The bisimide had a solubility of 5% by weight or more indichloromethane, chloroform and carbon tetrachloride, and also had goodprocessability.

EXAMPLE 17

The same procedures as conducted in Example 16 were carried out exceptthat 325.6 g(2.2 moles) of phthalic anhydride was replaced 436 g(2.2moles) of 2,3-naphthalenedicarboxylic anhydride. White powder obtainedwas 703 g(92% yield), had a melting point of 253° C., and gave followingresults on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.48 H.sub.32 N.sub.2 O.sub.6 S)                                  C    H         N      S                                           ______________________________________                                        Calculated (%)                                                                              75.39  4.19      3.66 4.19                                      Found (%)     75.52  4.26      3.42 3.88                                      ______________________________________                                    

In an IR absorption spectrum atlas, characteristic absorption band ofimide around 1780 cm⁻¹ and 1720 cm⁻¹ was remarkably found. On the otherhand, characteristic absorption band of amic acid around 1550 cm⁻¹,characteristic absorption band of diamine around 3200˜3400 cm⁻¹, andcharacteristic absorption band of acid anhydride around 1850 cm⁻¹ werenot found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum atlas, the powder thusobtained is bisimide having the structure of the formula(34): ##STR97##

The bisimide had a solubility of 5% by weight or

more in dichloromethane, chloroform and carbon tetrachloride and alsohad good processability.

Synthesis Example Synthesis of Polyimide-1

According to the example described Japanese Laid-Open Patent. Hei2-18419, 3,3'-diaminobenzophenone was reacted with 3,3',4,4'-benzophenonetetracarboxylic dianhydride in the presence of phthalicanhydride to obtain polyimide powder.

The polyimide powder had an inherent viscosity of 0.52 dl/g, glasstransition temperature of 250° C. and melting point of 298° C.

The inherent viscosity was measured at 35° C. in a solution containing0.5 g of the polyimide in a solvent mixture of p-chlorophenol/phenol ina ratio of 90/10 by weight. The melting point was measured by DSC. Themeasuring methods will be the same hereinafter.

Synthesis of Polyimide-2

The same procedures as conducted in Synthesis of Polyimide-1 werecarried out except that the ratio of the diamine to the tetracarboxylicacid dianhydride and phthalic anhydride was changed. The polyimidepowder thus obtained had an inherent viscosity of 0.85 dl/g, glasstransition temperature of 262° C. and melting point of 298° C.

Synthesis of Polyimide-3

According to the description in Japanese Laid-Open Patent Hei 1-110530,4,4'-bis(3-aminophenoxy)biphenyl was reacted with pyromelliticdianhydride and phthalic anhydride to obtain polyimide powder.

The polyimide powder obtained had an inherent viscosity of 0.53 dl/g,glass transition temperature of 250° C. and melting point of 390° C.

Synthesis of Polyimide-4

The same procedures as conducted in Synthesis of Polyimide-3 werecarried out except that the ratio of the diamine to tetracarboxylic aciddianhydride and phthalic anhydride was changed.

The polyimide powder thus obtained had an inherent viscosity of 0.78dl/g, glass transition temperature of 254° C. and melting point of 390°C.

Synthesis of Polyimide-5

The same procedures as conducted in Synthesis of Polyimide-3 werecarried out by using bis[4-(3-aminophenoxy)phenyl]sulfide, pyromelliticdianhydride and phthalic anhydride.

The polyimide thus obtained had an inherent viscosity of 0.49 dl/g andglass transition temperature of 235° C.

Synthesis of Polyimide-6

The same procedures as conducted in Synthesis of Polyimide-3 werecarried out by using bis[4-(3-aminophenoxy)phenyl]ketone,bis(3,4-dicarboxyphenyl)ether dianhydride and phthalic anhydride.

The polyimide thus obtained had an inherent viscosity of 0.51 dl/g andglass transition temperature of 201° C.

Synthesis of Polyimide-7

According to Japanese Laid-Open Patent Hei 1-221428,bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone was reacted withpyromellitic dianhydride and phthalic anhydride.

The polyimide thus obtained had an inherent viscosity of 0.57 dl/g,glass transition temperature of 285° C. and melting point of 420° C.

Synthesis of Polyimides-8˜12

The same procedures as conducted in Synthesis of Polyimide-7 werecarried out except that tetracarboxylic acid dianhydride was changed toobtain various kinds of polyimide.

The raw materials and properties of these polyimides and the results onPolyimide-7 are summarized in Table 2.

                                      TABLE 2                                     __________________________________________________________________________    Raw Material                     Polymer properties                                           Tetracarboxylic                                                                        Dicarboxylic                                                                          Inherent                                                                              Glass transition                                                                       Melting                     Polyimide                                                                           Diamine   acid dianhydride                                                                       acid anhydride                                                                        viscosity (dl/g)                                                                      temperature (°C.)                                                               point                       __________________________________________________________________________                                                      (°C.)                 7    bis[4-{4-(4-amino-                                                                      pyromellitic                                                                           phthalic                                                                              0.57    285      420                               phenoxy) phenoxy}                                                                       dianhydride                                                                            anhydride                                                  phenyl]sulfone                                                           8    ↑   ↑  ↑ 0.70    288      420                          9    ↑   3,3',4,4'-biphenyl-                                                                    ↑ 0.60    263      --                                          tetracarboxylic                                                               dianhydride                                                   10    ↑   bis(3,4-dicarboxy-                                                                     ↑ 0.59    237      --                                          phenyl)ether dian-                                                            hydride                                                       11    ↑   3,3',4,4'-benzo-                                                                       ↑ 0.60    245      --                                          phenonetetracarb-                                                             oxylic dianhydride                                            12    ↑   4,4'-(p-phenylene-                                                                     ↑ 0.59    220      --                                          dioxy) diphthalic                                                             dianhydride                                                   __________________________________________________________________________

Synthesis of Bisimide Compound-1

Bisimide was prepared from 4,4'-bis(3-aminophenoxy)biphenyl and phthalicanhydride by carrying out the same procedures as Example 1. The bisimidecompound obtained had a melting point of 286° C.

Synthesis of Bisimide Compound-2

Bisimide was prepared from bis[4-(3-aminophenoxy)phenyl]sulfide andphthalic anhydride by the same procedures as conducted in Synthesis ofBisimide Compound-1.

The bisimide compound thus obtained had a melting point of 230° C.

Synthesis of Bisimide Compound-3

To a reaction vessel equipped with a stirrer, reflux condenser andnitrogen inlet tube, 200 g(1.0 mole) of 4,4'-diaminodiphenyl ether and4000 g of m-cresol were charged and 311 g(2.1 moles) of phthalicanhydride was added at room temperature. The mixture was then heated to200° C. and stirred for 2 hours at the same temperature.

Successively, the reaction mixture was poured into methanol. Theprecipitate formed was filtered, washed several times with methanol anddried at 150° C. for 2 hours. The white powder thus obtained was 450 g,had a melting point of 295° C. and melt-initiation point of about 290°C., and also had good melt-processability.

Following results were obtained on elemental analysis.

    ______________________________________                                        Elemental analysis (C.sub.28 H.sub.16 N.sub.2 O.sub.4)                                   C         H      N                                                 ______________________________________                                        Calculated (%)                                                                             73.36       3.06   6.11                                          Found (%)    73.30       3.10   6.16                                          ______________________________________                                    

An IR absorption spectrum atlas is illustrated in FIG. 10. In thespectrum atlas, the characteristic absorption band of imide around 1780cm⁻¹ and 1720 cm⁻¹ and the characteristic absorption band of etheraround 1240 cm⁻¹ were remarkably found.

According to the identification by the preparation process, results ofelemental analysis and IR absorption spectrum, the powder thus obtainedis bisimide having the structure of the formula(35): ##STR98##

Synthesis of Bisimide Compound-4

Bismide was prepared from 3,3'-diaminobenzophenone and phthalicanhydride by carrying out the same procedures as conducted in Example 5.

The bisimide compound obtained had a melting point of 240° C.

Synthesis of Bisimide Compound-5

Bisimide was prepared from 4,4'-bis(4-aminophenoxy)biphenyl and phthalicanhydride by carrying out the same procedures as conducted inExample-12.

Synthesis of Bisimide Compounds-6˜12

The same procedures as conducted in Synthesis of Bisimide Compound-5were carried out except that diamines were changed to obtain variouskinds of bisimide.

Table 3 summarizes the raw materials and properties of the bisimide andalso results on Aromatic Bisimide Compound-5.

                  TABLE 3                                                         ______________________________________                                        Raw material               Bisimide                                                                  Dicarboxylic                                                                              Melting                                    Bisimide                                                                             Diamine         acid anhydride                                                                            point (°C.)                         ______________________________________                                        5      4,4'-bis(4-aminophenoxy)                                                                      Phthalic    292                                               biphenyl        anhydride                                              6      2,2-bis[4-(4-aminophen-                                                                       ↑     218                                               oxy)phenyl]propane                                                     7      1,3-bis(4-amino-α,α-                                                              ↑     240                                               dimethylbenzyl)benzene                                                 8      bis[4-{4-(4-aminophen-                                                                        ↑     217                                               oxy)phenoxy} phenyl]-                                                         sulfone                                                                9      bis[3-{4-(4-aminophen-                                                                        ↑     202                                               oxy)benzoyl} phenyl]-                                                         ether                                                                  10     bis[4-{4-(4-amino-α,α-                                                            ↑     160                                               dimethylbenzyl)phen-                                                          oxy} phenyl]sulfone                                                    11     1,4-bis[4-(3-aminophen-                                                                       ↑     220                                               oxy)benzoyl]benzene                                                    12     1,3-bis[4-(4-aminophen-                                                                       ↑     180                                               oxy)α,α-dimethylbenzyl]                                           benzene                                                                ______________________________________                                    

EXAMPLES 18˜20 Comparative Example 2

Polyimide-1 and Bisimide Compound-1 were dry blended in proportionsillustrated in Table 4. Melt viscosity of the resin composition obtainedwas measured with a Koka type flow tester CFT-500 (Trade mark ofShimadzu Seisa Kusho Co.) by using an orifice having a diameter of 0.1cm and a length of 1 cm. The resin composition was maintained in thecylinder at 380° C. for 5 minutes and then extruded under a load of 100kg. Results are illustrated in Table 4.

Melt viscosity rapidly decreased with increase in the proportion of thebisimide compound, and thus illustrated improvement of processability.

EXAMPLES 21˜23 Comparative Example 3

Polyimide-2 and Bisimide Compound-2 were dry blended in proportionsillustrated in Table 4. Melt viscosity of the resulting composition wasmeasured by the same procedures as conducted a in Examples 18˜20,Comparative Example 2 except that the resin composition was maintainedat 400° C. for 5 minutes in the cylinder of the flow tester. Resultsobtained are illustrated in Table 4.

EXAMPLES 24˜26

The same procedures as conducted in Examples 18˜20 were carried outexcept that Bisimide Compound-3 was used in place of Bisimide Compound-1and dry blended in proportions illustrated in Table 4. Melt viscositywas measured by extruding under 100 kg load after maintaining at 380° C.for 5 minutes. Results are illustrated in Table 4.

                  TABLE 4                                                         ______________________________________                                                                       Melt                                           Polyimide        Bisimide      viscosity                                      (wt. part)       (wt. part)    (poise)                                        ______________________________________                                        Example 18                                                                            Polyimide-1                                                                             100    Bisimide 1    8000                                   Example 19        100    Compound-1                                                                             5    6300                                   Example 20        100             20   1800                                   Compar-           100             0    10500                                  ative                                                                         Example 2                                                                     Example 21                                                                            Polyimide-2                                                                             100    Bisimide 2    91400                                  Example 22        100    Compound-2                                                                             10   51400                                  Example 23        100             50   2500                                   Compar-           100             0    120000                                 ative                                                                         Example 3                                                                     Example 24                                                                            Polyimide-1                                                                             100    Bisimide 5    6400                                   Example 25        100    Compound-3                                                                             20   1800                                   Example 26        100             70   **<100                                 ______________________________________                                         **: Melt viscosity is less than 100 poise and a measurement of melt           viscosity was not possible.                                              

EXAMPLES 27˜32 Comparative Example 4

Polyimide-3 and Bisimide Compound-1 or Bisimide Compound-3 were dryblended in proportions illustrated in Table 5. Melt viscosity of theresin composition obtained was measured with a Koka type flow testerCFT-500 (Trade mark of Shimadzu Seisakusho Co.) by using an orificehaving a diameter of 0.1 cm and a length of 1 cm. The resin compositionwas maintained in the cylinder at 400° C. for 5 minutes and thenextruded under a load of 100 kg. Results are illustrated in Table 5.

Melt viscosity rapidly decreased with increase in the proportion of thebisimide compound, and thus illustrated improvement of processability.

EXAMPLES 33˜35 Comparative Example 5

Polyimide-5 and Bisimide Compound-2 were dry blended in proportionsillustrated in Table 5. Melt viscosity of the resulting composition wasmeasured by the same procedures as conducted in Examples 27˜32,Comparative Example 4 except that the resin composition was maintainedat 360° C. for 5 minutes in the cylinder of the flow tester. Resultsobtained are illustrated in Table 5.

EXAMPLE 36˜38 Comparative Example 6

Polyimide-6 and Bisimide Compound-1 were dry blended in proportionsillustrated in Table 5. Melt viscosity of the resulting composition wasmeasured by extruding under 100 k g load after maintaining at 340° C.for 5 minutes in the cylinder of the flow tester. Results areillustrated in Table 5.

                  TABLE 5                                                         ______________________________________                                                                       Melt                                           Polyimide        Bisimide      viscosity                                      (wt. part)       (wt. part)    (poise)                                        ______________________________________                                        Example 27                                                                            Polyimide-3                                                                             100    Bisimide 1    5100                                   Example 28        100    Compound-1                                                                             5    3600                                   Example 29        100             20   1000                                   Compar-           100             0    6000                                   ative                                                                         Example 4                                                                     Example 30                                                                            Polyimide-3                                                                             100    Bisimide 2    4900                                   Example 31        100    Compound-3                                                                             10   2700                                   Example 32        100             50    150                                   Example 33                                                                            Polyimide-5                                                                             100    Bisimide 5    5500                                   Example 34        100    Compound-2                                                                             20   1500                                   Example 35        100             70   **<100                                 Compar-           100             0    9000                                   ative                                                                         Example 5                                                                     Example 36                                                                            Polyimide-6                                                                             100    Bisimide 1    6400                                   Example 37        100    Compound-1                                                                             5    4500                                   Example 38        100             20   1300                                   Compar-           100             0    8000                                   ative                                                                         Example 6                                                                     ______________________________________                                    

EXAMPLES 39˜42 Comparative Example 7

Polyimide-1 and Bisimide Compound-4 were dry blended in proportionsillustrated in Table 6. Melt viscosity of the resin composition obtainedwas measured with a Koka Type flow tester CFT-500 (Trade mark ofShimadzu Seisakusho Co.) by using an orifice having a diameter of 0.1 cmand a length of 1 cm. The resin composition was maintained in thecylinder at 380° C. for 5 minutes and then extruded under a load of 100k g. Results are illustrated in Table 6.

Melt viscosity rapidly decreased with increase in the proportion of thebisimide compound, and thus illustrated improvement of processability.

EXAMPLES 43˜45 Comparative Example 8

Polyimide-2 and Bisimide Compound-4 were dry blended in proportionsillustrated in Table 6. Melt viscosity of the resulting composition wasmeasured by the same procedures as conducted in Examples 39˜42 exceptthat the resin composition was maintained at 400° C. for 5 minutes inthe cylinder of the flow tester. Results are illustrated in Table 6.

                  TABLE 6                                                         ______________________________________                                                                       Melt                                           Polyimide        Bisimide      viscosity                                      (wt. part)       (wt. part)    (poise)                                        ______________________________________                                        Example 39                                                                            Polyimide-1                                                                             100    Bisimide 1    8100                                   Example 40        100    Compound-4                                                                             5    5700                                   Example 41        100             20   1600                                   Example 42        100             70   **<100                                 Compar-           100             0    10500                                  ative                                                                         Example 7                                                                     Example 43                                                                            Polyimide-2                                                                             100    Bisimide 2    77000                                  Example 44        100    Compound-4                                                                             10   43700                                  Example 45        100             50   2300                                   Compar-           100             0    120000                                 ative                                                                         Example 8                                                                     ______________________________________                                    

EXAMPLES 46˜51 Comparative Example 9

Polyimide-3 and Bisimide Compound-5 or Bisimide Compound-7 were dryblended in proportions illustrated in Table 7. Melt viscosity of theresin composition obtained was measured with a Koka Type flow testerCFT-500 (Trade mark of Shimadzu Seisakusho Co.) by using an orificehaving a diameter of 0.1 cm and a length of 1 cm. The resin compositionwas maintained in the cylinder at 400° C. for 5 minutes and thenextruded under a load of 100 kg. Results are illustrated in Table 7.

Melt viscosity rapidly decreased with increase in the proportion of thebisimide compound, and thus illustrated improvement of processability.

EXAMPLES 52˜57 Comparative Example 10

Polyimide-4 and Bisimide Compound-5 or Bisimide Compound-11 were dryblended in proportions illustrated in Table 7. Melt viscosity of theresulting composition was measured by the same procedures as conductedin Examples 46˜51, Comparative Example 9.

EXAMPLES 58˜63 Comparative Example 11

Polyimide-5 and Bisimide Compound-6 or Bisimide Compound-8 were dryblended in proportions illustrated in Table 7. Melt viscosity ofresulting polyimide composition was measured by extruding under load of100 kg after maintaining at 360° C. for 5 minutes in the cylinder of theflow tester. Results are illustrated in Table 7.

EXAMPLES 63˜71 Comparative Example 12

Polyimide-6 and Bisimide Compounds-9, -10 or -12 were dry blended inproportions illustrated in Table 7. Melt viscosity of the resultingpolyimide composition was measured by extruding under load of 100 kgafter maintaining at 340° C. for 5 minutes in the cylinder of the flowtester. Results are illustrated in Table 7.

                  TABLE 7                                                         ______________________________________                                                                       Melt                                           Polyimide        Bisimide      viscosity                                      (wt. part)       (wt. part)    (poise)                                        ______________________________________                                        Example 46                                                                            Polyimide-3                                                                             100    Bisimide 1    5200                                   Example 47        100    Compound-5                                                                             5    3500                                   Example 48        100             20   1100                                   Compar-           100             0    6000                                   ative                                                                         Example 9                                                                     Example 49        100    Bisimide 2    4800                                   Example 50        100    Compound-7                                                                             10   2500                                   Example 51        100             40   200                                    Example 52                                                                            Polyimide-4                                                                             100    Bisimide 2    83000                                  Example 53        100    Compound-5                                                                             10   46000                                  Example 54        100             25   6000                                   Compar-           100             0    370000                                 ative                                                                         Example 10                                                                    Example 55        100    Bisimide 5    72000                                  Example 56        100    Compound-11                                                                            15   15000                                  Example 57        100             30   1300                                   Example 58                                                                            Polyimide-5                                                                             100    Bisimide 2    7400                                   Example 59        100    Compound-6                                                                             10   3800                                   Example 60        100             15   2400                                   Compar-           100             0    9000                                   ative                                                                         Example 11                                                                    Example 61        100    Bisimide 5    5800                                   Example 62        100    Compound-8                                                                             20   1500                                   Example 63        100             30   640                                    Example 63                                                                            Polyimide-6                                                                             100    Bisimide 2    6800                                   Example 64        100    Compound-9                                                                             5    5200                                   Example 65        100             10   3400                                   Compar-           100             0    8000                                   ative                                                                         Example 12                                                                    Example 66        100    Bisimide 10   3300                                   Example 67        100    Compound-10                                                                            20   1400                                   Example 68        100             55   **<100                                 Example 69        100    Bisimide 1    7200                                   Example 70        100    Compound-12                                                                            5    5200                                   Example 71        100             10   3200                                   ______________________________________                                    

EXAMPLES 72˜77 Comparative Example 13

Polyimide-7 and B is imide Compound-1 or Bisimide Compound-3 were dryblended in proportions illustrated in Table 8. Melt viscosity of theresin composition obtained was measured with a Koka Type flow testerCFT-500 (Trade mark of Shimadzu Seisakusho Co.) by using an orificehaving a diameter of 0.1 cm and a length of 1 cm. The resin compositionwas maintained in the cylinder at 420° C. for 5 minutes and thenextruded under a load of 100 kg. Results are illustrated in Table 8.

Melt viscosity rapidly decreased with increase in the proportion of thebisimide compound, and thus illustrated improvement of processability.

EXAMPLES 78˜83 Comparative Example 14

Polyimide-8 and Bisimide Compound-5 or Bisimide Compound-7 were dryblended in proportions illustrated in Table 8. Melt viscosity of theresulting composition was measured by the same procedures as conductedin Examples 72˜77, Comparative Example 13.

EXAMPLES 84˜89 Comparative Example 15

Polyimide-9 and Bisimide Compound-1 or Bisimide Compound-8 were dryblended in proportions illustrated in Table 8. Melt viscosity ofresulting polyimide composition was measured by extruding under load of100 kg after maintaining at 380° C. for 5 minutes in the cylinder of theflow tester. Results are illustrated in Table 8.

EXAMPLES 90˜93 Comparative Example 16

Polyimide-10 and Bisimide Compounds-9 or -11 were dry blended inproportions illustrated in Table 8. Melt viscosity of the resultingpolyimide composition was measured by extruding under load of 100 kgafter maintaining at 360° C. for 5 minutes in the cylinder of the flowtester. Results are illustrated in Table 8.

EXAMPLES 94˜96 Comparative Example 17

Polyimide-11 and Bisimide Compound-12 were dry blended in proportionsillustrated in Table 8. Melt viscosity of the resulting composition wasmeasured by extruding under load of 100 kg after maintaining at 370° C.for 5 minutes in the cylinder of the flow tester. Results areillustrated in Table 8.

EXAMPLES 97˜99 Comparative Example 18

Polyimide-12 and Bisimide Compound-10 were dry blended in proportionsillustrated in Table 8. Melt viscosity was measured by extruding underload of 100 kg after maintaining at 340° C. for 5 minutes in thecylinder of the flow tester. Results are illustrated in Table 8.

By the addition of bisimide, melt viscosity of the resin was remarkablydecreased and processability was improved.

                  TABLE 8                                                         ______________________________________                                                                       Melt                                           Polyimide        Bisimide      viscosity                                      (wt. part)       (wt. part)    (poise)                                        ______________________________________                                        Example 72                                                                            Polyimide-7                                                                             100    Bisimide 1    7200                                   Example 73        100    Compound-1                                                                             5    5000                                   Example 74        100             10   3200                                   Compar-           100             0    8500                                   ative                                                                         Example 13                                                                    Example 75        100    Bisimide 5    5400                                   Example 76        100    Compound-3                                                                             15   2400                                   Example 77        100             25   1000                                   Example 78                                                                            Polyimide-8                                                                             100    Bisimide 2    46000                                  Example 79        100    Compound-5                                                                             10   17000                                  Example 80        100             30   1300                                   Compar-           100             0    68000                                  ative                                                                         Example 14                                                                    Example 81        100    Bisimide 5    34000                                  Example 82        100    Compound-7                                                                             15   8000                                   Example 83        100             30   1000                                   Example 84                                                                            Polyimide-9                                                                             100    Bisimide 10   4200                                   Example 85        100    Compound-1                                                                             30   700                                    Example 86        100             60   **<100                                 Compar-           100             0    10000                                  ative                                                                         Example 15                                                                    Example 87        100    Bisimide 5    5400                                   Example 88        100    Compound-8                                                                             10   3600                                   Example 89        100             20   1500                                   Example 90                                                                            Poly-     100    Bisimide 2    5000                                   Example 91                                                                            imide-10  100    Compound-9                                                                             5    3400                                   Compar-           100             0    6000                                   ative                                                                         Example 16                                                                    Example 92        100    Bisimide 10   2200                                   Example 93        100    Compound-11                                                                            15   1200                                   Example 94                                                                            Poly-     100    Bisimide 10   3000                                   Example 95                                                                            imide-11  100    Compound-12                                                                            30   300                                    Example 96        100             50   **<100                                 Compar-           100             0    9500                                   ative                                                                         Example 17                                                                    Example 97                                                                            Poly-     100    Bisimide 2    4000                                   Example 98                                                                            imide-12  100    Compound-10                                                                            5    2800                                   Example 99        100             10   1400                                   Compar-           100             0    5500                                   ative                                                                         Example 18                                                                    ______________________________________                                    

EXAMPLES 100˜102

The bisimide compound which was prepared by reacting4,4'-bis(3-aminophenoxy)biphenyl with phthalic anhydride according toExample 1 and had an inherent viscosity of 0.52 dl/g, glass transitiontemperature of 250° C. and melting point of 298° C. (hereinafterreferred to simply as Bisimide-A) was used as a raw material. A bisimidesolution compound of 20% by weight of Bisimide-A, 40% by weight ofdichloromethane and 40% by weight of 1,1,2-trichloroethane was prepared.

An oxidation-treated acrylic carbon fiber roving, HTA(Trade mark of TohoRayon Co.; used as carbon fiber in the below examples and comparativeexamples, unless otherwise noted ) was continuously immersed in thebisimide solution at a rate of 60 m/hr, dried to remove the solvents andcut into a length of 3 mm to obtain chopped strand. The adhered amountof the bisimide was 5% by weight for the weight of the carbon fiber. Thecarbon fiber chopped strand thus obtained was dry blended withPolyimide-4 in proportions illustrated in Table 9. The resin compositionthus obtained was fed to an extruder having a bore diameter of 40 mm,melt-kneaded at 400° C. and extruded to obtain uniformly blendedpellets.

The above uniform pellets were injection molded with a common injectionmolding machine at a cylinder temperature of 410° C. and moldtemperature of 200° C. to form dumbbell specimens. Tensile strength ofthe dumbbell specimens was measured at 23° C. at a pulling rate of 5mm/min.

Results are illustrated in Table 9.

Comparative Examples 19˜20

The same procedures as conducted in Examples 100˜102 were carried outexcept that the carbon fiber chopped strand coated with the bisimidecompound was replaced by an epoxyresin collected acrylic carbon fiber,Dumbbell specimens of carbon fiber reinforced polyimide resin thusprepared were subjected to tensile strength test and results areillustrated in Table 9,

                                      TABLE 9                                     __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber Tensile                                             Kind of                                                                              Amount                                                                              Collecting                                                                           Amount                                                                              strength                                            resin  (wt. %)                                                                             agent  (wt. %)                                                                             (kg/cm.sup.2)                                __________________________________________________________________________    Example 100                                                                          Polyimide-4                                                                          80    Bisimide A                                                                           20    2610                                         Example 101   70           30    3060                                         Example 102   60           40    3400                                         Comparative                                                                          Polyimide-4                                                                          80    epoxy  20    1880                                         Example 19          resin                                                     Comparative   70           30    2060                                         Example 20                                                                    Comparative   60           40    2200                                         Example 21                                                                    __________________________________________________________________________

EXAMPLES 103˜105

The bisimide compound which was prepared by reactingbis[4-(3-aminophenoxy)phenyl]sulfide with phthalic anhydride accordingto Example 3 and had a melting point of 230° C. (hereinafter referred tosimply as Bisimide-B) was used as a raw material.

As oxidation-treated carbon fiber roving was continuously immersed inmolten Bisimide-B at 240° C. at a rate of 30 m/hr and cut into a lengthof 3 mm to obtain chopped strand. The amount of adhered bisimidecompound was 7% by weight for the weight of carbon fiber.

The carbon fiber chopped strand thus obtained was dry blended withPolyimide-5 in proportions illustrated in Table 10. The resincomposition obtained was fed to an extruder having a bore diameter of 40mm, melt-kneaded at 360° C. and extruded to obtain uniformly blendedpellets.

The above uniform pellets were injection molded with a common injectionmolding machine at a cylinder temperature of 360° C. and moldtemperature of 180° C. to form dumbbell specimens. Tensile strength ofthe dumbbell specimens was measured at 23° C. at a pulling rate of 5mm/min. Results are illustrated in Table 10.

Comparative Examples 22˜23

The same procedures as conducted in Examples 102˜104 were carried outexcept that proportions of the bisimide coated carbon fiber werechanged. Results are illustrated in Table 10. Pellets containing 60% byweight of carbon fiber had poor melt flowability and hence dumbbellspecimens could not be prepared by injection molding.

                                      TABLE 10                                    __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber                                                                              Tensile                                              Kind of                                                                              Amount                                                                              Collecting                                                                          Amount                                                                              strength                                             resin  (wt. %)                                                                             agent (wt. %)                                                                             (kg/cm.sup.2)                                 __________________________________________________________________________    Example 103                                                                          Polyimide-5                                                                          80    Bisimide-B                                                                          20    2970                                          Example 104   70          30    3450                                          Example 105   60          40    3880                                          Comparative                                                                          Polyimide-5                                                                          40    epoxy 60    molding                                       Example 22          resin       impossible                                    Comparative   98          20    1650                                          Example 23                                                                    __________________________________________________________________________

EXAMPLES 106˜108

The same procedures as conducted in Examples 100˜102 were carried outexcept that Polyimide-4 was replaced by Polyimide-6 and the compositionwas melt-kneaded at 320° C. to obtain uniformly blended pellets. Thepellets thus obtained was injection molded with a common injectionmolding machine at a cylinder temperature of 330° C. and moldtemperature of 160° C. to prepare dumbbell specimens. Tensile strengthof the dumbbell specimens was measured at 23° C. at a pulling rate of 5mm/min. Results are illustrated in Table 11.

Comparative Example 24

Dumbbell specimens were prepared by carrying out the same procedures asconducted in Examples 106˜108 except that the polyimide resin was usedalone without carbon fiber. Results are illustrated in Table 11.

                                      TABLE 11                                    __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber Tensile                                             Kind of                                                                              Amount                                                                              Collecting                                                                           Amount                                                                              strength                                            resin  (wt. %)                                                                             agent  (wt. %)                                                                             (kg/cm.sup.2)                                __________________________________________________________________________    Example 106                                                                          Polyimide-6                                                                          80    Bisimide-A                                                                           20    2600                                         Example 107   70           30    2910                                         Example 108   60           40    3260                                         Comparative                                                                          Polyimide-6                                                                          100   Bisimide-A                                                                            0    1180                                         Example 24                                                                    __________________________________________________________________________

EXAMPLES 109-111

Uniformly blended pellets were prepared by carrying out the. sameprocedures as conducted in Examples 106˜108 except that Polyimide-6 isreplaced by polyimide-1 and the composition was melt-kneaded at 360° C.

Dumbbell specimens were prepared from the uniformly blended pellets byinjection molding at a cylinder temperature of 380° and mold temperature180° C. Tensile strength of the specimens was measured at 23° C. at apulling rate of 5 mm/min. Results are illustrated in Table 12.

Comparative Example 25˜27

Dumbbell specimens of carbon fiber reinforced polyimide resin wereprepared by carrying out the same procedures as conducted in Examples109˜111 except that the carbon fiber chopped strand coated with thebisimide compound was replaced by an acrylic carbon fiber collected withan epoxy resin. Tensile strength of the specimens was measured under thesame conditions as in Examples 109˜111 and results are illustrated inTable 12.

                                      TABLE 12                                    __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber Tensile                                             Kind of                                                                              Amount                                                                              Collecting                                                                           Amount                                                                              strength                                            resin  (wt. %)                                                                             agent  (wt. %)                                                                             (kg/cm.sup.2)                                __________________________________________________________________________    Example 109                                                                          Polyimide-1                                                                          80    Bisimide-A                                                                           20    2680                                         Example 110   70           30    3120                                         Example 111   60           40    3510                                         Comparative                                                                          Polyimide-1                                                                          80    epoxy  20    1930                                         Example 25          resin                                                     Comparative   70           30    2100                                         Example 26                                                                    Comparative   60           40    2270                                         Example 27                                                                    __________________________________________________________________________

EXAMPLES 112˜114

A bisimide solution composed of 40% by weight of dichloromethane, 40% byweight of 1,1,2-trichloroethane and 20% by weight of BisimideCompound-3(hereinafter referred to simply as Bisimide-C) was prepared.An oxidation-treated acrylic carbon fiber roving, HTA(Trade Mark of TohoRayon Co.) was continuously immersed in the bisimide solution at a rateof 60 m/hr, dried to remove the solvents and cut into a length of 3 mmto obtain chopped strand. The adhered amount of the bisimide was 5% byweight for the weight of the carbon fiber.

The carbon fiber chopped strand thus obtained was dry blended withpolyimide-4 in proportions illustrated in Table 13. The resincomposition thus obtained was fed to an extruder having a bore diameterof 40 mm, melt-kneaded at 400° C. and extruded to obtain uniformlyblended pellets.

The above uniform pellets were injection molded with a common injectionmolding machine at a cylinder temperature of 400° C. and moldtemperature of 200° C. to form dumbbell specimens. Tensile strength ofthe dumbbell specimens was measured at 23° C. at a pulling rate of 5mm/min. Results are illustrated in Table 13.

Comparative Examples 28˜30

The same procedures as conducted in Examples 112˜114 were carried outexcept that the carbon fiber chopped strand coated with the bisimidecompound was replaced by an epoxy-resin collected acrylic carbon fiber.Dumbbell specimens of carbon fiber reinforced polyimide resin thusprepared were subjected to tensile strength test and results areillustrated in Table 13.

                                      TABLE 13                                    __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber Tensile                                             Kind of                                                                              Amount                                                                              Collecting                                                                           Amount                                                                              strength                                            resin  (wt. %)                                                                             agent  (wt. %)                                                                             (kg/cm.sup.2)                                __________________________________________________________________________    Example 112                                                                          Polyimide-4                                                                          80    Bisimide-C                                                                           20    2630                                         Example 113   70           30    3080                                         Example 114   60           40    3430                                         Comparative                                                                          Polyimide-4                                                                          80    epoxy  20    1880                                         Example 28          resin                                                     Comparative   70           30    2060                                         Example 29                                                                    Comparative   60           40    2200                                         Example 30                                                                    __________________________________________________________________________

EXAMPLES 115˜117

A carbon fiber roving which was previously oxidation-treated on thesurface was continuously immersed in molten Bisimide-C at a rate of 30m/hr and cut into a length of 3 mm to obtain chopped strand.

The adhered amount of the bisimide was 5% by weight for the weight ofthe carbon fiber.

The carbon fiber chopped strand thus obtained was dry blended withpolyimide-5 in proportions illustrated in Table 14. The resincomposition thus obtained was fed to an extruder having a bore diameterof 40 mm, melt-kneaded at 360° C. and extruded to obtain uniformlyblended pellets.

The above uniform pellets were injection molded with a common injectionmolding machine at a cylinder temperature of 360° C. and moldtemperature of 180° C. to form dumbbell specimens. Tensile strength ofthe dumbbell specimens was measured at 23° C. at a pulling rate of 5mm/min. Results are illustrated in Table 14.

Comparative Examples 31˜32

The same procedures as conducted in Examples 115˜117 were carried outexcept that the proportion of the polyimide to the carbon fiber coatedwith the bisimide was changed. Results are illustrated in Table 14.

The pellets containing 60% by weight of carbon fiber had poor meltflowability and hence dumbbell specimens could not be prepared byinjection molding.

                                      TABLE 14                                    __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber Tensile                                             Kind of                                                                              Amount                                                                              Collecting                                                                           Amount                                                                              strength                                            resin  (wt. %)                                                                             agent  (wt. %)                                                                             (kg/cm.sup.2)                                __________________________________________________________________________    Example 115                                                                          Polyimide-5                                                                          80    Bisimide-C                                                                           20    2980                                         Example 116   70           30    3500                                         Example 117   60           40    3950                                         Comparative                                                                          Polyimide-5                                                                          40    Bisimide-C                                                                           60    molding                                      Example 31                       impossible                                   Comparative   98            2    1650                                         Example 32                                                                    __________________________________________________________________________

EXAMPLES 118˜120

Uniformly blended pellets were prepared by carrying out the. sameprocedures as conducted in Examples 112˜114 except that Polyimide-4 isreplaced by Polyimide-6 and melt-kneading was carried out at 320° C. Theuniform pellets obtained were injection molded with a common injectionmolding machine at a cylinder temperature of 320° C. and moldtemperature of 160° C. to prepare dumbbell specimens. Tensile strengthof the specimens was measured at 23° C. at a pulling rate of 5 mm/min.Results are illustrated in Table 15.

Comparative Example 33

Dumbbell specimens were prepared by carrying out the same procedures asconducted in Examples 118˜120 except that polyimide resin was used alonewithout carbon fiber. Results are illustrated in Table 15.

                                      TABLE 15                                    __________________________________________________________________________           Composition                                                                   Polyimide resin                                                                            Carbon fiber Tensile                                             Kind of                                                                              Amount                                                                              Collecting                                                                           Amount                                                                              strength                                            resin  (wt. %)                                                                             agent  (wt. %)                                                                             (kg/cm.sup.2)                                __________________________________________________________________________    Example 118                                                                          Polyimide-6                                                                          80    Bisimide-C                                                                           20    2630                                         Example 119   70           30    3000                                         Example 120   60           40    3320                                         Comparative                                                                          Polyimide-6                                                                          100   Bisimide-C                                                                            0    1180                                         Example 33                                                                    __________________________________________________________________________

The polyimide resin composition of the present invention is acomposition comprising an aromatic bisimide compound in polyimide resinand has improved processability.

The resin composition of the invention composed of an improved carbonfiber and polyimide resin can be processed into a desired shape byinjection molding, extrusion forming, transfer molding, compressionmolding and other known processing methods.

The resin composition of the invention thus processed has excellentmechanical strength, particularly mechanical strengths at hightemperatures, and hence can be used for mechanical members andautomotive parts which require high mechanical strengths at hightemperatures, for example, gear, cam, bushing, pulley and sleeve, andalso for members of internal combustion engines, for example, gasexhausting parts for a silencer such as an impeller and manifold of anintegrated centrifugal compressor, valve guide, valve stem, pistonskirt, oil pan, front cover and locker cover.

The carbon fiber reinforced polyimide resin composition of the inventionis usually used in the form of pellets which can be handled with ease.Molded articles are prepared by injection molding. The pellets areprepared by kneading and extruding the polyimide resin and the carbonfiber strand with a known single or twin screw extruder and successivelyby cutting the resulting strand of the composition.

Injection molding of the pellets thus obtained is carried out with acommon injection molding machine at a cylinder temperature of 360° to420° C. and a mold temperature of 160° to 210° C., preferably 180° to200° C. Complex shaped members of internal combustion engines such as animpeller of an integrated centrifugal compressor can also be preparedwith ease.

The carbon fiber reinforced polyimide resin composition of the inventionhas excellent mechanical strength and can be widely used as a materialfor members of electric and electronic devices, automotive trim, spaceand aeronautical equipment and general instruments in industry. Thus,the polyimide resin composition is valuable in industry.

Further, the bisimide compound of the invention is very useful for thepreparation of the polyimide resin composition having these excellentproperties.

I claim:
 1. A bisimide compound represented by the formula(1): ##STR99##wherein A is a divalent radical selected from the group consisting ofradicals having the formulas: ##STR100## wherein X is a direct bond, adivalent hydrocarbon radical having from 1 to 10 carbon atoms,hexafluorinated isopropylidene, carbonyl, thio or sulfonyl, and Y₁ ˜Y₄are individually hydrogen atom, lower alkyl radical, lower alkoxyradical, chlorine or bromine atom, ##STR101## and R is a divalentradical selected from the group consisting of a monoaromatic radical,condensed polyaromatic radical and noncondensed aromatic radicalconnected to each other with a direct bond or a bridge member.
 2. Abisimide compound represented by the formula(2): ##STR102## wherein X isa direct bond, a divalent hydrocarbon radical having from 1 to 10 carbonatoms, hexafluorinated isopropylidene, carbonyl, thio or sulfonyl, Y₁˜Y₄ are individually hydrogen, lower alkyl radical, lower alkoxyradical, chlorine or bromine atom, and R is a divalent radical selectedfrom the group consisting of a monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected to eachother with a direct bond or a bridge member.
 3. A bisimide compoundrepresented by the formula(3): ##STR103## wherein R is a divalentradical selected from the group consisting of a monoaromatic radical,condensed polyaromatic radical and noncondensed aromatic radicalconnected to each other with a direct bond or a bridge member.
 4. Abisimide compound represented by the formula(4): ##STR104## wherein R isa divalent radical selected from the group consisting of a monoaromaticradical, condensed polyaromatic radical and noncondensed aromaticradical connected to each other with a direct bond or a bridge member.5. A bisimide compound represented by the formula(5): ##STR105## whereinR is a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember.
 6. A bisimide compound represented by the formula(6): ##STR106##wherein R is a divalent radical selected from the group consisting of amonoaromatic radical, condensed polyaromatic radical and noncondensedaromatic radical connected to each other with a direct bond or a bridgemember.
 7. A bisimide compound represented by the formula(7): ##STR107##wherein X is a direct bond, a divalent hydrocarbon radical having from 1to 10 carbon atoms, hexafluorinated isopropylidene, carbonyl, thio orsulfonyl, Y₁ ˜Y₄ are individually hydrogen, lower alkyl radical, loweralkoxy radical, chlorine or bromine atom, and R is a divalent radicalselected from the group consisting of a monoaromatic radical, condensedpolyaromatic radical and noncondensed aromatic radical connected to eachother with a direct bond or a bridge member.